Answer in brief
CVE-2026-107719 records a Medium severity (CVSS 4.2) vulnerability in fast-jwt: Verifier cache accepts expired JWTs without iat.. The current sources do not mark it as known exploited. The current feed maps nearform/fast-jwt (generic), fast-jwt (npm), fast-jwt (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 4.2. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps nearform/fast-jwt (generic), fast-jwt (npm), fast-jwt (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| nearform/fast-jwtgeneric | <6.3.4 | 6.3.4 |
| fast-jwtnpm | <=6.3.3 | 6.3.4 |
| fast-jwtnpm | >=0 <6.3.4 | 6.3.4 |
Published upstream
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 8, 2026
fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.3.4, the fast-jwt createVerifier cache can continue accepting a previously valid, signed JWT after its exp time when caching is enabled and the token has exp but no iat. In src/verifier.js, cacheSet derives the exp cache deadline only when iat is present, so the cache falls back to cacheTTL, and a later cache hit returns the saved payload before verifyToken rechecks expiration. An attacker who can replay the same cached bearer token can extend access until the cache entry expires, but cannot forge a token through this issue. This issue is fixed in version 6.3.4.
Quoted source text, attributed separately from HOL analysis.