fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.3.0, fast-jwt createVerifier accepts Infinity for clockTolerance because its option validation checks type and negativity but not finiteness. In validateClaimDateValue, infinite positive and negative modifiers make exp and nbf comparisons always pass, allowing expired or not-yet-active tokens to be accepted. The verifier cache also derives infinite bounds, so entries created under this configuration can remain valid until eviction. Exploitation requires an application administrator or equivalent configuration path to set clockTolerance to Infinity. This issue is fixed in version 6.3.0.
Project Subscriptions
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Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-687g-22h4-j4w4 | fast-jwt clockTolerance: Infinity silently bypasses both exp and nbf validation (and persists in the verifier cache) |
Fixes
Solution
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Workaround
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References
History
Thu, 08 Oct 2026 22:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.3.0, fast-jwt createVerifier accepts Infinity for clockTolerance because its option validation checks type and negativity but not finiteness. In validateClaimDateValue, infinite positive and negative modifiers make exp and nbf comparisons always pass, allowing expired or not-yet-active tokens to be accepted. The verifier cache also derives infinite bounds, so entries created under this configuration can remain valid until eviction. Exploitation requires an application administrator or equivalent configuration path to set clockTolerance to Infinity. This issue is fixed in version 6.3.0. | |
| Title | fast-jwt clockTolerance: Infinity silently bypasses both exp and nbf validation (and persists in the verifier cache) | |
| Weaknesses | CWE-613 CWE-682 |
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| References |
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| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-10-08T21:45:57.545Z
Reserved: 2026-10-08T17:21:52.975Z
Link: CVE-2026-107721
No data.
Status : Deferred
Published: 2026-10-08T22:17:28.263
Modified: 2026-10-08T22:17:28.410
Link: CVE-2026-107721
No data.
OpenCVE Enrichment
No data.
Github GHSA