CVE-2026-107721

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Source
https://cve.org/CVERecord?id=CVE-2026-107721
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-107721.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-107721
Aliases
Published
2026-10-08T21:45:57Z
Modified
2026-10-09T10:46:07Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Summary
fast-jwt clockTolerance: Infinity silently bypasses both exp and nbf validation (and persists in the verifier cache)
Details

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.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-613",
        "CWE-682"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/107xxx/CVE-2026-107721.json"
}
References

Affected packages

Git / github.com/nearform/fast-jwt

Affected ranges

Type
GIT
Repo
https://github.com/nearform/fast-jwt
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
b351e31a755cdce457e0d25ce22b139bbcf469da
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "6.3.0"
        }
    ],
    "source": "AFFECTED_FIELD"
}

Affected versions

v0.*
v0.1.0
v0.1.1
v0.2.0
v0.3.0
v0.3.1
v0.4.0
v0.4.1
v0.4.2
v0.5.0
v0.5.1
v1.*
v1.0.0
v1.1.0
v1.1.1
v1.1.2
v1.1.3
v1.2.0
v1.3.0
v1.3.2
v1.4.0
v1.4.1
v1.5.0
v1.5.1
v1.5.2
v1.5.3
v1.5.4
v1.6.0
v1.6.1
v1.7.0
v1.7.1
v1.7.2
v2.*
v2.0.0
v6.*
v6.1.0
v6.2.0
v6.2.1
v6.2.2
v6.2.3
v6.2.4

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-107721.json"