fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.1, using certain modifiers on RegExp objects in the allowedAud, allowedIss, allowedSub, allowedJti, or allowedNonce options in verify functions can cause certain unint…
Exact source revision recorded 27 Oct 2026 09:03:08 UTC. It does not establish the source's current position. Latest evidence.
nvd · CVE-2026-35040
Publishedfast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.1, using certain modifiers on RegExp objects in the allowedAud, allowedIss, allowedSub, allowedJti, or allowedNonce options in verify functions can cause certain unintended behaviours. This is because some modifiers are stateful and will cause failures in every second verification attempt regardless of the validity of the token provided. Such modifiers are /g (global matching) and /y (sticky matching). This does NOT allow invalid tokens to be accepted, only for valid tokens to be improperly rejected in some configurations. Instead it causes 50% of valid authentication requests to fail in an alternating pattern. This vulnerability is fixed in 6.2.1.
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Analyzed
Weakness classifications: CWE-440 · CWE-697
Original publisher date fields
published: 2026-04-09T16:16:27.213
lastModified: 2026-10-26T21:10:00.170
1 source CPE criteria · context only
- cpe:2.3:a:nearform:fast-jwt:*:*:*:*:*:node.js:*:*
The original JSON retains the logical configuration operators, exclusions and version bounds.
- Source published
- 9 Apr 2026 16:16:27 UTC
- Source modified
- 26 Oct 2026 21:10:00 UTC
- Observed here
- 27 Oct 2026 09:03:08 UTC
- Source terms
- NIST NVD usage terms; underlying source attribution retained
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.
CVSS 3.1 · [email protected] · Secondary · 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L