{"items":[{"id":"NVI-00002209","kind":"vulnerability","title":"league/commonmark: Denial of service via colliding heading slugs","revision":4,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected.","NVD lastModified does not establish freshness of every associated CPE record."],"lifecycle":"active","identifiers":["GHSA-mh25-x5hq-wrqp","CVE-2026-86434"],"plain_summary":"GitHub lists this reviewed advisory for league/commonmark. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-0f2d23eab4b79a3068857153f58833ee"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 2.9.0 for league/commonmark. Confirm the publisher’s latest guidance.","source_ids":["sr-0fb0ed3a3ecf10a80f442e5bf56a7ad2"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-08-06T20:41:46.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-579bf2436b7b79cba42bfc8232e28f1e"},{"kind":"CVSS","as_of":"2026-10-08T16:17:57.953Z","value":"7.5 HIGH (3.1)","meaning":"disclosure@vulncheck.com severity; no combined Null risk score.","source_id":"sr-4109d14dd4505cd0d2d09daddf3be141"},{"kind":"CVSS","as_of":"2026-10-08T16:17:57.953Z","value":"8.7 HIGH (4.0)","meaning":"disclosure@vulncheck.com severity; no combined Null risk score.","source_id":"sr-4109d14dd4505cd0d2d09daddf3be141"},{"kind":"EPSS","as_of":"2026-11-03T12:00:27.000Z","value":"0.509%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.43534. Missing scores are unknown.","source_id":"sr-0f2d23eab4b79a3068857153f58833ee"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-579bf2436b7b79cba42bfc8232e28f1e","url":"https://github.com/advisories/GHSA-mh25-x5hq-wrqp","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-mh25-x5hq-wrqp","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T02:28:46.523Z"},{"id":"sr-0fb0ed3a3ecf10a80f442e5bf56a7ad2","url":"https://github.com/advisories/GHSA-mh25-x5hq-wrqp","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-mh25-x5hq-wrqp","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:42:30.979Z"},{"id":"sr-4109d14dd4505cd0d2d09daddf3be141","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-86434","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2026-86434","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-01T07:25:08.112Z"},{"id":"sr-0f2d23eab4b79a3068857153f58833ee","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-86434","publisher":"FIRST EPSS","observed_at":"2026-11-03T17:45:16.084Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-579bf2436b7b79cba42bfc8232e28f1e"],"technology":"league/commonmark","known_exclusions":[],"conditions_summary":"### Impact\n\n`UniqueSlugNormalizer::normalize()` makes each slug document-unique by searching for an unused numeric suffix, but **restarts that search from `1` on every collision**. The k-th heading that collapses to the same base slug performs k−1 array lookups, so K colliding slugs cost Σ(k−1) = **O(K²)**. An attacker can force every heading onto a single base slug trivially — many empty ATX headings, identical heading text, or punctuation-only headings that normalize to the empty string.\n\nThe path is reached whenever the shared slug normalizer runs over attacker-controlled text. That happens when `HeadingPermalinkExtension` is registered (its `HeadingPermalinkProcessor` normalizes every heading), independently through `FootnoteExtension` (its `AnonymousFootnoteRefParser` normalizes every `^[label]` reference), and on any `TableOfContentsExtension` site (which requires `HeadingPermalinkExtension` to be co-registered). The default `slug_normalizer/unique` setting (`UniqueSlugNormalizerInterface::PER_DOCUMENT`) accumulates collisions across the whole document. No authentication is required — a small document body turns into seconds of CPU and denies service. Availability impact only","public_affected_ranges":[">= 2.0.0, < 2.9.0"]},{"certainty":"source_listed","source_ids":["sr-0fb0ed3a3ecf10a80f442e5bf56a7ad2"],"technology":"league/commonmark","known_exclusions":[],"conditions_summary":"### Impact\n\n`UniqueSlugNormalizer::normalize()` makes each slug document-unique by searching for an unused numeric suffix, but **restarts that search from `1` on every collision**. The k-th heading that collapses to the same base slug performs k−1 array lookups, so K colliding slugs cost Σ(k−1) = **O(K²)**. An attacker can force every heading onto a single base slug trivially — many empty ATX headings, identical heading text, or punctuation-only headings that normalize to the empty string.\n\nThe path is reached whenever the shared slug normalizer runs over attacker-controlled text. That happens when `HeadingPermalinkExtension` is registered (its `HeadingPermalinkProcessor` normalizes every heading), independently through `FootnoteExtension` (its `AnonymousFootnoteRefParser` normalizes every `^[label]` reference), and on any `TableOfContentsExtension` site (which requires `HeadingPermalinkExtension` to be co-registered). The default `slug_normalizer/unique` setting (`UniqueSlugNormalizerInterface::PER_DOCUMENT`) accumulates collisions across the whole document. No authentication is required — a small document body turns into seconds of CPU and denies service. Availability impact only","public_affected_ranges":["ECOSYSTEM: introduced 2.0.0; fixed 2.9.0"]}],"null_published_at":"2026-11-06T00:29:57.276Z","source_updated_at":"2026-08-06T20:41:46.000Z","source_disclosed_at":"2026-08-06T20:41:45.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.","null_first_observed_at":"2026-10-31T21:42:30.979Z"},{"id":"NVI-00002209","kind":"vulnerability","title":"league/commonmark: Denial of service via colliding heading slugs","revision":3,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected.","NVD lastModified does not establish freshness of every associated CPE record."],"lifecycle":"active","identifiers":["GHSA-mh25-x5hq-wrqp","CVE-2026-86434"],"plain_summary":"GitHub lists this reviewed advisory for league/commonmark. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-4109d14dd4505cd0d2d09daddf3be141"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 2.9.0 for league/commonmark. Confirm the publisher’s latest guidance.","source_ids":["sr-0fb0ed3a3ecf10a80f442e5bf56a7ad2"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-08-06T20:41:46.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-579bf2436b7b79cba42bfc8232e28f1e"},{"kind":"CVSS","as_of":"2026-10-08T16:17:57.953Z","value":"7.5 HIGH (3.1)","meaning":"disclosure@vulncheck.com severity; no combined Null risk score.","source_id":"sr-4109d14dd4505cd0d2d09daddf3be141"},{"kind":"CVSS","as_of":"2026-10-08T16:17:57.953Z","value":"8.7 HIGH (4.0)","meaning":"disclosure@vulncheck.com severity; no combined Null risk score.","source_id":"sr-4109d14dd4505cd0d2d09daddf3be141"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-579bf2436b7b79cba42bfc8232e28f1e","url":"https://github.com/advisories/GHSA-mh25-x5hq-wrqp","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-mh25-x5hq-wrqp","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T02:28:46.523Z"},{"id":"sr-0fb0ed3a3ecf10a80f442e5bf56a7ad2","url":"https://github.com/advisories/GHSA-mh25-x5hq-wrqp","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-mh25-x5hq-wrqp","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:42:30.979Z"},{"id":"sr-4109d14dd4505cd0d2d09daddf3be141","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-86434","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2026-86434","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-01T07:25:08.112Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-579bf2436b7b79cba42bfc8232e28f1e"],"technology":"league/commonmark","known_exclusions":[],"conditions_summary":"### Impact\n\n`UniqueSlugNormalizer::normalize()` makes each slug document-unique by searching for an unused numeric suffix, but **restarts that search from `1` on every collision**. The k-th heading that collapses to the same base slug performs k−1 array lookups, so K colliding slugs cost Σ(k−1) = **O(K²)**. An attacker can force every heading onto a single base slug trivially — many empty ATX headings, identical heading text, or punctuation-only headings that normalize to the empty string.\n\nThe path is reached whenever the shared slug normalizer runs over attacker-controlled text. That happens when `HeadingPermalinkExtension` is registered (its `HeadingPermalinkProcessor` normalizes every heading), independently through `FootnoteExtension` (its `AnonymousFootnoteRefParser` normalizes every `^[label]` reference), and on any `TableOfContentsExtension` site (which requires `HeadingPermalinkExtension` to be co-registered). The default `slug_normalizer/unique` setting (`UniqueSlugNormalizerInterface::PER_DOCUMENT`) accumulates collisions across the whole document. No authentication is required — a small document body turns into seconds of CPU and denies service. Availability impact only","public_affected_ranges":[">= 2.0.0, < 2.9.0"]},{"certainty":"source_listed","source_ids":["sr-0fb0ed3a3ecf10a80f442e5bf56a7ad2"],"technology":"league/commonmark","known_exclusions":[],"conditions_summary":"### Impact\n\n`UniqueSlugNormalizer::normalize()` makes each slug document-unique by searching for an unused numeric suffix, but **restarts that search from `1` on every collision**. The k-th heading that collapses to the same base slug performs k−1 array lookups, so K colliding slugs cost Σ(k−1) = **O(K²)**. An attacker can force every heading onto a single base slug trivially — many empty ATX headings, identical heading text, or punctuation-only headings that normalize to the empty string.\n\nThe path is reached whenever the shared slug normalizer runs over attacker-controlled text. That happens when `HeadingPermalinkExtension` is registered (its `HeadingPermalinkProcessor` normalizes every heading), independently through `FootnoteExtension` (its `AnonymousFootnoteRefParser` normalizes every `^[label]` reference), and on any `TableOfContentsExtension` site (which requires `HeadingPermalinkExtension` to be co-registered). The default `slug_normalizer/unique` setting (`UniqueSlugNormalizerInterface::PER_DOCUMENT`) accumulates collisions across the whole document. No authentication is required — a small document body turns into seconds of CPU and denies service. Availability impact only","public_affected_ranges":["ECOSYSTEM: introduced 2.0.0; fixed 2.9.0"]}],"null_published_at":"2026-11-03T10:03:26.568Z","source_updated_at":"2026-08-06T20:41:46.000Z","source_disclosed_at":"2026-08-06T20:41:45.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-10-31T21:42:30.979Z"},{"id":"NVI-00002209","kind":"vulnerability","title":"league/commonmark: Denial of service via colliding heading slugs","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected.","NVD lastModified does not establish freshness of every associated CPE record."],"lifecycle":"active","identifiers":["GHSA-mh25-x5hq-wrqp","CVE-2026-86434"],"plain_summary":"OSV carries this publisher advisory for league/commonmark. This is an aggregated source copy; consult the original publisher and compare update dates.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"The original advisory lists fixed boundaries 2.9.0 for league/commonmark. Confirm the publisher’s latest guidance.","source_ids":["sr-0fb0ed3a3ecf10a80f442e5bf56a7ad2"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-4109d14dd4505cd0d2d09daddf3be141"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-08T16:17:57.953Z","value":"7.5 HIGH (3.1)","meaning":"disclosure@vulncheck.com severity; no combined Null risk score.","source_id":"sr-4109d14dd4505cd0d2d09daddf3be141"},{"kind":"CVSS","as_of":"2026-10-08T16:17:57.953Z","value":"8.7 HIGH (4.0)","meaning":"disclosure@vulncheck.com severity; no combined Null risk score.","source_id":"sr-4109d14dd4505cd0d2d09daddf3be141"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-0fb0ed3a3ecf10a80f442e5bf56a7ad2","url":"https://github.com/advisories/GHSA-mh25-x5hq-wrqp","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-mh25-x5hq-wrqp","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:42:30.979Z"},{"id":"sr-4109d14dd4505cd0d2d09daddf3be141","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-86434","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2026-86434","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-01T07:25:08.112Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-0fb0ed3a3ecf10a80f442e5bf56a7ad2"],"technology":"league/commonmark","known_exclusions":[],"conditions_summary":"### Impact\n\n`UniqueSlugNormalizer::normalize()` makes each slug document-unique by searching for an unused numeric suffix, but **restarts that search from `1` on every collision**. The k-th heading that collapses to the same base slug performs k−1 array lookups, so K colliding slugs cost Σ(k−1) = **O(K²)**. An attacker can force every heading onto a single base slug trivially — many empty ATX headings, identical heading text, or punctuation-only headings that normalize to the empty string.\n\nThe path is reached whenever the shared slug normalizer runs over attacker-controlled text. That happens when `HeadingPermalinkExtension` is registered (its `HeadingPermalinkProcessor` normalizes every heading), independently through `FootnoteExtension` (its `AnonymousFootnoteRefParser` normalizes every `^[label]` reference), and on any `TableOfContentsExtension` site (which requires `HeadingPermalinkExtension` to be co-registered). The default `slug_normalizer/unique` setting (`UniqueSlugNormalizerInterface::PER_DOCUMENT`) accumulates collisions across the whole document. No authentication is required — a small document body turns into seconds of CPU and denies service. Availability impact only","public_affected_ranges":["ECOSYSTEM: introduced 2.0.0; fixed 2.9.0"]}],"null_published_at":"2026-11-01T14:34:07.636Z","source_updated_at":"2026-10-20T12:11:18.651Z","source_disclosed_at":"2026-08-06T20:41:45.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-10-31T21:42:30.979Z"},{"id":"NVI-00002209","kind":"vulnerability","title":"league/commonmark: Denial of service via colliding heading slugs","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-mh25-x5hq-wrqp","CVE-2026-86434"],"plain_summary":"OSV carries this publisher advisory for league/commonmark. This is an aggregated source copy; consult the original publisher and compare update dates.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"The original advisory lists fixed boundaries 2.9.0 for league/commonmark. Confirm the publisher’s latest guidance.","source_ids":["sr-0fb0ed3a3ecf10a80f442e5bf56a7ad2"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-0fb0ed3a3ecf10a80f442e5bf56a7ad2","url":"https://github.com/advisories/GHSA-mh25-x5hq-wrqp","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-mh25-x5hq-wrqp","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:42:30.979Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-0fb0ed3a3ecf10a80f442e5bf56a7ad2"],"technology":"league/commonmark","known_exclusions":[],"conditions_summary":"### Impact\n\n`UniqueSlugNormalizer::normalize()` makes each slug document-unique by searching for an unused numeric suffix, but **restarts that search from `1` on every collision**. The k-th heading that collapses to the same base slug performs k−1 array lookups, so K colliding slugs cost Σ(k−1) = **O(K²)**. An attacker can force every heading onto a single base slug trivially — many empty ATX headings, identical heading text, or punctuation-only headings that normalize to the empty string.\n\nThe path is reached whenever the shared slug normalizer runs over attacker-controlled text. That happens when `HeadingPermalinkExtension` is registered (its `HeadingPermalinkProcessor` normalizes every heading), independently through `FootnoteExtension` (its `AnonymousFootnoteRefParser` normalizes every `^[label]` reference), and on any `TableOfContentsExtension` site (which requires `HeadingPermalinkExtension` to be co-registered). The default `slug_normalizer/unique` setting (`UniqueSlugNormalizerInterface::PER_DOCUMENT`) accumulates collisions across the whole document. No authentication is required — a small document body turns into seconds of CPU and denies service. Availability impact only","public_affected_ranges":["ECOSYSTEM: introduced 2.0.0; fixed 2.9.0"]}],"null_published_at":"2026-10-31T21:54:04.901Z","source_updated_at":"2026-10-20T12:11:18.651Z","source_disclosed_at":"2026-08-06T20:41:45.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-10-31T21:42:30.979Z"}],"next_cursor":null,"snapshot_revision":"42594"}