{"schema":"threatline.record/2","record":{"id":"GHSA-r4xh-jqrq-34v2","aliases":["GHSA-r4xh-jqrq-34v2"],"summary":"smol-toml: Quadratic-time parse() from parseKey rescanning to end of document on each key line","details":"### Summary\n\n`parse()` has a quadratic-time path in `parseKey`, reachable on default options with ordinary valid input. For every key line and table-header line, `parseKey` (dist/struct.js, lines 58 and 86) finds the dotted-key separator with `ctx.s.indexOf('.', ctx.p)`, where `ctx.s` is the whole document. When a key has no `.` ahead of it, that search runs all the way to the end of the input, and the result is then clamped back to the line terminator `endPtr` - so everything scanned past the current line is wasted. `parseKey` runs once per line, so a document of N dot-free keys costs O(n^2).\n\nThe most ordinary TOML shape triggers it: a flat list of `key = value` lines, or a repeated `[[a]]` table. No dotted keys, no special options, valid input throughout.\n\n### Proof of concept\n\n```js\nimport { parse } from 'smol-toml'\n\nlet doc = ''\nfor (let i = 0; i < 256000; i++) doc += 'k' + i + ' = 1\\n'\n\nconsole.time('parse')\nparse(doc) // ~2.8 MB of valid TOML, default options\nconsole.timeEnd('parse')\n```\n\nDoubling the line count roughly quadruples the time:\n\n| lines | size | parse() |\n|---|---|---|\n| 32k | 0.3 MB | 0.3 s |\n| 64k | 0.7 MB | 1.0 s |\n| 128k | 1.4 MB | 3.5 s |\n| 256k | 2.8 MB | 14 s |\n\n### Impact\nAny service that runs `parse()` on attacker-supplied TOML can be stalled. The work is synchronous, so it blocks the whole event loop, and the quadratic is unbounded: a ~7 MB body pins a core for about a minute, larger bodies for several.\n\n### Patches\nVersion 1.9.0 uses a different implementation for parsing keys which is strictly linear.\n\n### Workarounds\nLimit the maximum document size accepted when parsing arbitrary documents.","categories":["Libraries & packages"],"product":"smol-toml","vendor":"","ecosystem":"npm","affected_ranges":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-r4xh-jqrq-34v2","source_modified_at":"2026-10-05T23:41:15Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"smol-toml"},"range":"<= 1.8.0"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-r4xh-jqrq-34v2","source_modified_at":"2026-10-06T00:00:08.430664986Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"smol-toml","ecosystem":"npm","purl":"pkg:npm/smol-toml"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.9.0"}]}],"versions":[]}],"fixed_versions":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-r4xh-jqrq-34v2","source_modified_at":"2026-10-05T23:41:15Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"smol-toml"},"version":"1.9.0"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-r4xh-jqrq-34v2","source_modified_at":"2026-10-06T00:00:08.430664986Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"smol-toml","ecosystem":"npm","purl":"pkg:npm/smol-toml"},"version":"1.9.0"}],"cvss":5.3,"severity":"Medium","kev":{"listed":false},"epss":{"probability":null,"percentile":null,"score_date":null},"published_at":"2026-10-05T23:41:14Z","modified_at":"2026-10-06T00:00:08.430664986Z","provenance":[{"source":"GitHub Advisory Database","url":"https://github.com/advisories/GHSA-r4xh-jqrq-34v2","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-05T23:41:15Z"},{"source":"OSV","url":"https://osv.dev/vulnerability/GHSA-r4xh-jqrq-34v2","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-06T00:00:08.430664986Z"}],"sources":["GitHub Advisory Database","OSV"],"references":[{"url":"https://github.com/squirrelchat/smol-toml/security/advisories/GHSA-r4xh-jqrq-34v2","source":"GitHub Advisory Database"},{"url":"https://github.com/squirrelchat/smol-toml/commit/99102aa57fc932f760ea9c15b4cf1c181f952d24","source":"GitHub Advisory Database"},{"url":"https://github.com/squirrelchat/smol-toml/releases/tag/v1.9.0","source":"GitHub Advisory Database"},{"url":"https://github.com/advisories/GHSA-r4xh-jqrq-34v2","source":"GitHub Advisory Database"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"ecosystem","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-06T00:00:08.430664986Z","content_hash":"5e36a50937884b509401873c965ea1f6e291689b9f56cda2db789638bd56d73c"}}