{"cve":"CVE-2026-35039","nvd":{"published":"2026-04-06T17:17:13.243","modified":"2026-10-23T23:10:00.157","status":"Analyzed","description":"fast-jwt provides fast JSON Web Token (JWT) implementation. From 0.0.1 to before 6.2.0, setting up a custom cacheKeyBuilder method which does not properly create unique keys for different tokens can lead to cache collisions. This could cause tokens to be mis-identified during the verification process leading to valid tokens returning claims from different valid tokens and users being mis-identified as other users based on the wrong token. Version 6.2.0 contains a patch.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":9.1},"cwes":["CWE-345","CWE-706","CWE-1289"],"references":["https://github.com/nearform/fast-jwt/commit/de121056c6415b58770c60640881eaec67ac4ceb","https://github.com/nearform/fast-jwt/security/advisories/GHSA-rp9m-7r4c-75qg"],"products":["nearform:fast-jwt"],"source":"nvd","synced_at":"2026-10-24T16:53:27.712498749+00:00"},"epss":{"cve":"CVE-2026-35039","score":0.00212,"percentile":0.11414,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-rp9m-7r4c-75qg","url":"https://osv.dev/vulnerability/GHSA-rp9m-7r4c-75qg","summary":"fast-jwt: Cache Confusion via cacheKeyBuilder Collisions Can Return Claims From a Different Token (Identity/Authorization Mixup)","modified":"2026-04-08T12:02:30.353217Z","packages":[{"ecosystem":"npm","name":"fast-jwt","purl":"pkg:npm/fast-jwt","ranges":[">=0.0.1 <6.2.0"],"fixed":["6.2.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}