{"items":[{"id":"NVI-00006761","kind":"vulnerability","title":"league/commonmark:  Denial of service via duplicate footnote definitions","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-jfm3-95jq-q3rf"],"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-1690abe6c16447e9cb703e6cf76f21ed"],"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-c1c65ef04e7cf7e6a681d50a97993606"],"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":"2026-08-06T20:42:11.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-1690abe6c16447e9cb703e6cf76f21ed"}],"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-1690abe6c16447e9cb703e6cf76f21ed","url":"https://github.com/advisories/GHSA-jfm3-95jq-q3rf","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-jfm3-95jq-q3rf","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T02:28:46.523Z"},{"id":"sr-c1c65ef04e7cf7e6a681d50a97993606","url":"https://github.com/advisories/GHSA-jfm3-95jq-q3rf","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-jfm3-95jq-q3rf","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:42:20.441Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-1690abe6c16447e9cb703e6cf76f21ed"],"technology":"league/commonmark","known_exclusions":[],"conditions_summary":"### Impact\n\nThe Footnote extension records one backref per footnote *reference* and then appends the **entire** backref list for **every** footnote *definition* block in the document, without ever de-duplicating or removing repeated definitions of the same label (`GatherFootnotesListener`, populated by `NumberFootnotesListener`). A document that references a single label N times and also supplies N duplicate `[^a]:` definitions of that label therefore produces **N × N** `FootnoteBackref` nodes, so output size, parse time, and peak memory are all **O(N²)**.\n\nReaching the vulnerable path requires `FootnoteExtension` to be registered on the `Environment`. This is opt-in, but is a commonly enabled GFM-style feature; no other non-default configuration is required. An unauthenticated attacker can expand a **~10 KB** request into a **~62 MB** HTML response, **~3 s** of CPU, and **~440 MB** of peak memory — enough to OOM-kill a default 128 MB PHP worker and deny service. Availability impact only; no confidentiality or integrity effect. **The Footnote extension was introduced in 1.5.0 (May 2020) with this backref logic present from the first commit, so all releases from 1.5.0 onward (includ","public_affected_ranges":[">= 1.5.0, < 2.9.0"]},{"certainty":"source_listed","source_ids":["sr-c1c65ef04e7cf7e6a681d50a97993606"],"technology":"league/commonmark","known_exclusions":[],"conditions_summary":"### Impact\n\nThe Footnote extension records one backref per footnote *reference* and then appends the **entire** backref list for **every** footnote *definition* block in the document, without ever de-duplicating or removing repeated definitions of the same label (`GatherFootnotesListener`, populated by `NumberFootnotesListener`). A document that references a single label N times and also supplies N duplicate `[^a]:` definitions of that label therefore produces **N × N** `FootnoteBackref` nodes, so output size, parse time, and peak memory are all **O(N²)**.\n\nReaching the vulnerable path requires `FootnoteExtension` to be registered on the `Environment`. This is opt-in, but is a commonly enabled GFM-style feature; no other non-default configuration is required. An unauthenticated attacker can expand a **~10 KB** request into a **~62 MB** HTML response, **~3 s** of CPU, and **~440 MB** of peak memory — enough to OOM-kill a default 128 MB PHP worker and deny service. Availability impact only; no confidentiality or integrity effect. **The Footnote extension was introduced in 1.5.0 (May 2020) with this backref logic present from the first commit, so all releases from 1.5.0 onward (includ","public_affected_ranges":["ECOSYSTEM: introduced 1.5.0; fixed 2.9.0"]}],"null_published_at":"2026-11-03T10:03:26.542Z","source_updated_at":"2026-08-06T20:42:11.000Z","source_disclosed_at":"2026-08-06T20:40:53.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-10-31T21:42:20.441Z"},{"id":"NVI-00006761","kind":"vulnerability","title":"league/commonmark:  Denial of service via duplicate footnote definitions","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-jfm3-95jq-q3rf"],"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-c1c65ef04e7cf7e6a681d50a97993606"],"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-c1c65ef04e7cf7e6a681d50a97993606","url":"https://github.com/advisories/GHSA-jfm3-95jq-q3rf","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-jfm3-95jq-q3rf","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:42:20.441Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-c1c65ef04e7cf7e6a681d50a97993606"],"technology":"league/commonmark","known_exclusions":[],"conditions_summary":"### Impact\n\nThe Footnote extension records one backref per footnote *reference* and then appends the **entire** backref list for **every** footnote *definition* block in the document, without ever de-duplicating or removing repeated definitions of the same label (`GatherFootnotesListener`, populated by `NumberFootnotesListener`). A document that references a single label N times and also supplies N duplicate `[^a]:` definitions of that label therefore produces **N × N** `FootnoteBackref` nodes, so output size, parse time, and peak memory are all **O(N²)**.\n\nReaching the vulnerable path requires `FootnoteExtension` to be registered on the `Environment`. This is opt-in, but is a commonly enabled GFM-style feature; no other non-default configuration is required. An unauthenticated attacker can expand a **~10 KB** request into a **~62 MB** HTML response, **~3 s** of CPU, and **~440 MB** of peak memory — enough to OOM-kill a default 128 MB PHP worker and deny service. Availability impact only; no confidentiality or integrity effect. **The Footnote extension was introduced in 1.5.0 (May 2020) with this backref logic present from the first commit, so all releases from 1.5.0 onward (includ","public_affected_ranges":["ECOSYSTEM: introduced 1.5.0; fixed 2.9.0"]}],"null_published_at":"2026-10-31T22:13:10.072Z","source_updated_at":"2026-08-06T20:45:15.564Z","source_disclosed_at":"2026-08-06T20:40:53.000Z","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":"2026-10-31T21:42:20.441Z"}],"next_cursor":null,"snapshot_revision":"42594"}