CVE-2026-107724

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Source
https://cve.org/CVERecord?id=CVE-2026-107724
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-107724.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-107724
Aliases
Published
2026-10-08T21:53:01Z
Modified
2026-10-09T10:46:09Z
Severity
  • 7.4 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Summary
fast-jwt treats raw public JWK JSON as an HMAC secret, enabling HS256 token forgery
Details

fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.2.4, fast-jwt can classify raw serialized public JWK or JWKS JSON as an HMAC secret because src/crypto.js performDetectPublicKeyAlgorithms treats non-PEM strings as symmetric key material. If HS256 is explicitly allowed or inferred, an attacker who knows the exact serialized public-key bytes can use those bytes as an HMAC key and create a token containing arbitrary claims that createVerifier accepts. Serialization ordering or whitespace differences can prevent exploitation, and applications using supported PEM keys with an asymmetric-only algorithm allowlist are not affected. This issue is fixed in version 6.3.0.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-347"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/107xxx/CVE-2026-107724.json"
}
References

Affected packages

Git / github.com/nearform/fast-jwt

Affected ranges

Type
GIT
Repo
https://github.com/nearform/fast-jwt
Events
Introduced
044bf42c8e0a2eda8afc0819f97ae435c4214e3c
Fixed
b351e31a755cdce457e0d25ce22b139bbcf469da
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "6.2.4"
        },
        {
            "fixed": "6.3.0"
        }
    ],
    "source": "AFFECTED_FIELD"
}

Affected versions

v6.*
v6.2.4

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-107724.json"