{"items":[{"id":"NVI-00012110","kind":"vulnerability","title":"gomarkdown/markdown IsSafeURL panics on short URLs","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-cv23-7vc5-jfh7","CVE-2026-102941"],"plain_summary":"GitHub lists this reviewed advisory for github.com/gomarkdown/markdown. 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-2d0afb10bed5a3db9bd373b0a84a7cb7"],"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":"2026-10-16T15:41:44.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-a953a446586e3dcc1590a90d2804f573"},{"kind":"EPSS","as_of":"2026-10-31T12:00:27.000Z","value":"0.279%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.20376. Missing scores are unknown.","source_id":"sr-2d0afb10bed5a3db9bd373b0a84a7cb7"}],"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-a953a446586e3dcc1590a90d2804f573","url":"https://github.com/advisories/GHSA-cv23-7vc5-jfh7","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-cv23-7vc5-jfh7","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T23:14:14.588Z"},{"id":"sr-2d0afb10bed5a3db9bd373b0a84a7cb7","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-2026-102941","publisher":"FIRST EPSS","observed_at":"2026-11-01T01:39:43.063Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-a953a446586e3dcc1590a90d2804f573"],"technology":"github.com/gomarkdown/markdown","known_exclusions":[],"conditions_summary":"## Summary\n\nIsSafeURL slices url[:nPath] before checking that len(url) >= nPath, so a URL shorter than a path prefix (0, 1 or 2 bytes) triggers a slice-bounds panic, and this is reached end to end when the html.Safelink hardening flag is enabled and the input contains an empty or very short link destination, giving an unrecoverable crash DoS. Confirmed at HEAD (e08cff8; present since 2022).\n\n## The defect\n\nparser/parser.go, IsSafeURL:\n\n```go\nfunc IsSafeURL(url []byte) bool {\n    nLink := len(url)\n    for _, path := range validPaths {          // \"/\", \"./\", \"../\"\n        nPath := len(path)\n        linkPrefix := url[:nPath]               // line 789: sliced BEFORE the length guard\n        if nLink >= nPath && bytes.Equal(linkPrefix, path) {   // line 790: guard is too late\n            ...\n```\n\nurl[:nPath] is evaluated before the `nLink >= nPath` check. When len(url) < nPath and cap(url) < nPath, the slice expression panics. Only the relative-path loop is affected; the adjacent URIs loop is already correctly guarded (the signal that this one deviates, the same signal as the anchor). Input: IsSafeURL(\"\") panics ([:1] cap 0), IsSafeURL(\".\") panics ([:2] cap 1), IsSafeURL(\"..\") panics ([","public_affected_ranges":["< 0.0.0-20260724235538-61af6e1e6971"]}],"null_published_at":"2026-11-01T14:34:14.107Z","source_updated_at":"2026-10-16T15:41:44.000Z","source_disclosed_at":"2026-10-16T15:41:39.000Z","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":"2026-10-31T23:14:14.588Z"},{"id":"NVI-00012110","kind":"vulnerability","title":"gomarkdown/markdown IsSafeURL panics on short URLs","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-cv23-7vc5-jfh7","CVE-2026-102941"],"plain_summary":"GitHub lists this reviewed advisory for github.com/gomarkdown/markdown. 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-a953a446586e3dcc1590a90d2804f573"],"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":"2026-10-16T15:41:44.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-a953a446586e3dcc1590a90d2804f573"}],"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-a953a446586e3dcc1590a90d2804f573","url":"https://github.com/advisories/GHSA-cv23-7vc5-jfh7","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-cv23-7vc5-jfh7","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T23:14:14.588Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-a953a446586e3dcc1590a90d2804f573"],"technology":"github.com/gomarkdown/markdown","known_exclusions":[],"conditions_summary":"## Summary\n\nIsSafeURL slices url[:nPath] before checking that len(url) >= nPath, so a URL shorter than a path prefix (0, 1 or 2 bytes) triggers a slice-bounds panic, and this is reached end to end when the html.Safelink hardening flag is enabled and the input contains an empty or very short link destination, giving an unrecoverable crash DoS. Confirmed at HEAD (e08cff8; present since 2022).\n\n## The defect\n\nparser/parser.go, IsSafeURL:\n\n```go\nfunc IsSafeURL(url []byte) bool {\n    nLink := len(url)\n    for _, path := range validPaths {          // \"/\", \"./\", \"../\"\n        nPath := len(path)\n        linkPrefix := url[:nPath]               // line 789: sliced BEFORE the length guard\n        if nLink >= nPath && bytes.Equal(linkPrefix, path) {   // line 790: guard is too late\n            ...\n```\n\nurl[:nPath] is evaluated before the `nLink >= nPath` check. When len(url) < nPath and cap(url) < nPath, the slice expression panics. Only the relative-path loop is affected; the adjacent URIs loop is already correctly guarded (the signal that this one deviates, the same signal as the anchor). Input: IsSafeURL(\"\") panics ([:1] cap 0), IsSafeURL(\".\") panics ([:2] cap 1), IsSafeURL(\"..\") panics ([","public_affected_ranges":["< 0.0.0-20260724235538-61af6e1e6971"]}],"null_published_at":"2026-11-01T01:03:56.631Z","source_updated_at":"2026-10-16T15:41:44.000Z","source_disclosed_at":"2026-10-16T15:41:39.000Z","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":"2026-10-31T23:14:14.588Z"}],"next_cursor":null,"snapshot_revision":"42594"}