CVE-2026-107722

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Source
https://cve.org/CVERecord?id=CVE-2026-107722
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-107722.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-107722
Aliases
Published
2026-10-08T21:49:55Z
Modified
2026-10-09T10:46:04Z
Severity
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
fast-jwt: Incomplete patch of CVE-2026-34950: Non-whitespace key-prefix re-enables RSA→HS256 algorithm confusion
Details

fast-jwt provides fast JSON Web Token (JWT) implementation. From 6.2.0 until 6.3.0, fast-jwt can misclassify RSA public-key text as an HMAC secret when the key has non-whitespace content before its PEM header. In src/crypto.js, performDetectPublicKeyAlgorithms trims whitespace but publicKeyPemMatcher remains start-anchored, so comments, control characters, zero-width characters, or wrapper text can prevent PEM detection and reach the HMAC fallback. An attacker who knows the public key bytes can sign arbitrary HS256 claims with that public material when HS256 is inferred or allowed, resulting in authentication or authorization bypass. An asymmetric-only algorithm allowlist prevents the attack. 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-2026-107722.json"
}
References

Affected packages

Git / github.com/nearform/fast-jwt

Affected ranges

Type
GIT
Repo
https://github.com/nearform/fast-jwt
Events
Introduced
e07b1fd23f02a47f1be677a21a4f07607b478e66
Fixed
b351e31a755cdce457e0d25ce22b139bbcf469da
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "6.2.0"
        },
        {
            "fixed": "6.3.0"
        }
    ],
    "source": "AFFECTED_FIELD"
}

Affected versions

v6.*
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-2026-107722.json"