{"id":"CVE-2026-49293","aliases":["GHSA-wp3c-266w-4qfq"],"url":"https://o3.security/vulnerability/CVE-2026-49293","summary":"CPU exhaustion via O(n^2) BigInt construction on radix-prefixed integer literals","details":"js-toml is a TOML parser for JavaScript, fully compliant with the TOML 1.0.0 Spec. Versions up to and including 1.1.0 parse hexadecimal / octal / binary integer literals via a hand-written `parseBigInt` loop that multiplies a `BigInt` accumulator by the radix once per input digit. Each iteration performs a `BigInt * BigInt` operation on an accumulator that grows linearly with the number of digits already consumed, so the whole loop is O(n²) in the literal length. The lexer regex places no upper bound on the literal length, so a single TOML document containing one ~500 kB hex literal pins one CPU core for ~40 seconds on a modern laptop (Apple M-series, Node v22). Memory amplification is bounded but CPU amplification is severe and grows quadratically: doubling the literal length quadruples the work. A caller that invokes `load()` on attacker-controlled TOML (configuration upload endpoints, CI/CD systems ingesting third-party `*.toml`, IDE plugins, build tools) is exposed to a single-request CPU exhaustion DoS. Version 1.1.1 fixes the issue.","published":"2026-06-19T18:14:20.150Z","modified":"2026-08-12T03:51:30.018279431Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.0041,"percentile":0.33814,"asOf":"2026-08-11"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"js-toml","fixedVersion":"1.1.1"}],"fix":{"url":"https://github.com/sunnyadn/js-toml/commit/1abcb31dc7b1fa88e4c848a8d108891cfbb96fa2","label":"sunnyadn/js-toml@1abcb31"},"references":[{"type":"WEB","url":"https://github.com/sunnyadn/js-toml/releases/tag/v1.1.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49293.json"},{"type":"ADVISORY","url":"https://github.com/sunnyadn/js-toml/security/advisories/GHSA-wp3c-266w-4qfq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49293"},{"type":"FIX","url":"https://github.com/sunnyadn/js-toml/commit/1abcb31dc7b1fa88e4c848a8d108891cfbb96fa2"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:30.018279431Z"}}