{"items":[{"id":"NVI-00003513","kind":"vulnerability","title":"league/commonmark: Denial of service via adjacent inline attribute blocks","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-g2gp-3wwq-f4ph"],"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-414ad3cce01a270c65e28f30d15f75e6"],"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-414ad3cce01a270c65e28f30d15f75e6","url":"https://github.com/advisories/GHSA-g2gp-3wwq-f4ph","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-g2gp-3wwq-f4ph","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:42:20.409Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-414ad3cce01a270c65e28f30d15f75e6"],"technology":"league/commonmark","known_exclusions":[],"conditions_summary":"### Impact\n\nWith the Attributes extension enabled, `AttributesListener::findTargetAndDirection()` resolves each attribute node's target by walking outward through its siblings. For a run of N adjacent inline attribute blocks placed at the start of a block (with nothing to their left), each node scans the **entire** sibling list to the far-right end before giving up and falling back to the parent. Each resolution is therefore Θ(N) and the whole run is **Θ(N²)**.\n\nReaching the path requires `AttributesExtension` (opt-in, but first-party: `League\\CommonMark\\Extension\\Attributes\\AttributesExtension`). No other configuration matters — the quadratic walk runs unconditionally during parsing and is **not** gated by the `attributes/allow` allow-list, the `on*` hardening added in 2.7.0, or `allow_unsafe_links`. An unauthenticated attacker can submit a **~32 KB** input (`{#a}` repeated 8,000 times) that takes **over 5 seconds** to convert, with time growing quadratically in input length — a cheap denial of service. Availability impact only. **The Attributes extension was introduced in 1.5.0 (May 2020) with this outward-walk resolver present from the first commit, so all releases from 1.5.0 on","public_affected_ranges":["ECOSYSTEM: introduced 1.5.0; fixed 2.9.0"]}],"null_published_at":"2026-10-31T22:12:48.019Z","source_updated_at":"2026-08-06T20:45:15.558Z","source_disclosed_at":"2026-08-06T20:39:52.000Z","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":"2026-10-31T21:42:20.409Z"}],"next_cursor":null,"snapshot_revision":"40769"}