CVE Explorer
CVE-2026-35041
fast-jwt provides fast JSON Web Token (JWT) implementation. From 5.0.0 to 6.2.0, a denial-of-service condition exists in fast-jwt when the allowedAud verification option is configured using a regular expression. Because the aud claim is attacker-controlled and the library evaluates it against the supplied RegExp, a crafted JWT can trigger catastrophic backtracking in the JavaScript regex engine, resulting in significant CPU consumption during verification. This vulnerability is fixed in 6.2.1.
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"product":"fast-jwt","vendor":"nearform","versions":[{"status":"affected","version":">= 5.0.0, < 6.2.1"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:fa73e4e72a548b2a50d4baafe89f8fac3c4b7fc8f32164c8ae24548e8483427a · sha256:329a89fe891830d1… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":4.2,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"HIGH","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:fa73e4e72a548b2a50d4baafe89f8fac3c4b7fc8f32164c8ae24548e8483427a · sha256:329a89fe891830d1… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-1333","description":"CWE-1333: Inefficient Regular Expression Complexity","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:fa73e4e72a548b2a50d4baafe89f8fac3c4b7fc8f32164c8ae24548e8483427a · sha256:329a89fe891830d1… · /containers/cna/problemTypes/0/descriptions/0
Source references
5 source assertions{"name":"https://github.com/nearform/fast-jwt/commit/b0be0ca161593836a153d5180ca5358ad9b5de94","tags":["x_refsource_MISC"],"url":"https://github.com/nearform/fast-jwt/commit/b0be0ca161593836a153d5180ca5358ad9b5de94"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:fa73e4e72a548b2a50d4baafe89f8fac3c4b7fc8f32164c8ae24548e8483427a · sha256:329a89fe891830d1… · /containers/cna/references/2
{"name":"https://github.com/nearform/fast-jwt/pull/595","tags":["x_refsource_MISC"],"url":"https://github.com/nearform/fast-jwt/pull/595"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:fa73e4e72a548b2a50d4baafe89f8fac3c4b7fc8f32164c8ae24548e8483427a · sha256:329a89fe891830d1… · /containers/cna/references/1
{"name":"https://github.com/nearform/fast-jwt/releases/tag/v6.2.1","tags":["x_refsource_MISC"],"url":"https://github.com/nearform/fast-jwt/releases/tag/v6.2.1"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:fa73e4e72a548b2a50d4baafe89f8fac3c4b7fc8f32164c8ae24548e8483427a · sha256:329a89fe891830d1… · /containers/cna/references/3
{"tags":["exploit"],"url":"https://github.com/nearform/fast-jwt/security/advisories/GHSA-cjw9-ghj4-fwxf"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:fa73e4e72a548b2a50d4baafe89f8fac3c4b7fc8f32164c8ae24548e8483427a · sha256:329a89fe891830d1… · /containers/adp/0/references/0
{"name":"https://github.com/nearform/fast-jwt/security/advisories/GHSA-cjw9-ghj4-fwxf","tags":["x_refsource_CONFIRM"],"url":"https://github.com/nearform/fast-jwt/security/advisories/GHSA-cjw9-ghj4-fwxf"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:fa73e4e72a548b2a50d4baafe89f8fac3c4b7fc8f32164c8ae24548e8483427a · sha256:329a89fe891830d1… · /containers/cna/references/0
Attribution and limitations
- CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →
Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.