{"items":[{"id":"NVI-00016112","kind":"vulnerability","title":"Mistune inline_parser: quadratic-time parsing on long runs of `**x**` and `***x***` emphasis pairs","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-4j32-57v6-6g45","CVE-2026-59925"],"plain_summary":"GitHub lists this reviewed advisory for mistune. 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-24e2fc73777087ed9f7eb5a0de083e69"],"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":"2026-07-20T21:32:42.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-24e2fc73777087ed9f7eb5a0de083e69"}],"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-24e2fc73777087ed9f7eb5a0de083e69","url":"https://github.com/advisories/GHSA-4j32-57v6-6g45","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-4j32-57v6-6g45","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T22:35:18.117Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-24e2fc73777087ed9f7eb5a0de083e69"],"technology":"mistune","known_exclusions":[],"conditions_summary":"## Summary\n\n**Type:** Algorithmic-complexity DoS in core emphasis parsing. A long sequence of well-formed `**x**` (strong) or `***x***` (strong-emphasis combined) pairs causes O(N²) parser work. Distinct from the bracket-bomb DoS (`[` repetition) and from the formatting-plugin DoS (`~~`/`==`/`^^`); this one fires on default-config mistune with no plugins required.\n**File:** `src/mistune/inline_parser.py` lines 41-48 (the `EMPHASIS_END_RE` family) and the surrounding emphasis dispatch.\n**Root cause:** for every opening run of `*`s the parser scans forward using one of `EMPHASIS_END_RE['*']` / `['**']` / `['***']` to find the matching close. Each scan is bounded per call, but the parser invokes the scan from every potential start position. For input shaped `**x**` repeated N times, every `**` is treated as a potential start, each scan can cover up to the end of input. Total work is O(N²). The triple-emphasis variant `***x***` is slightly worse due to the extra alternation between `*`, `**`, and `***` close patterns. Reproducible against default mistune with no plugins.\n\n## Affected Code\n\n**File:** `src/mistune/inline_parser.py`, lines 41-48.\n\n```python\nEMPHASIS_END_RE = {\n    \"*\": re","public_affected_ranges":["< 3.3.0"]}],"null_published_at":"2026-11-04T10:04:27.894Z","source_updated_at":"2026-07-20T21:32:42.000Z","source_disclosed_at":"2026-07-20T21:32:40.000Z","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":"2026-11-03T22:35:18.117Z"}],"next_cursor":null,"snapshot_revision":"42594"}