CVE-2026-102272

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.prepare_key in jwt/algorithms.py is affected because raw-JWK detector does not normalize accepted Unicode byte-order marks before checking for JSON. This occurs when a public JWK is prefixed with a UTF-8 BOM and used in a mixed-algorithm verification path. As a result, public JWK bypasses asymmetric-key detection and becomes the HMAC secret. Consequently, an attacker who knows the public key can forge authenticated tokens. This issue is fixed in version 2.14.0.

Database specific

{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-347"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102272.json"
}

References

Affected packages

Git / github.com/jpadilla/pyjwt

Affected ranges

Type

GIT

Repo

https://github.com/jpadilla/pyjwt

Events

Introduced

7144e4534c34810f4525dc4578a32addd8212cff

Fixed

c6fe464b356ff4b1ebc9ba62172d331a40aa27df

Fixed

180783930de91876bc0d601f826a1f2956057291

Database specific

Show details

{
    "extracted_events": [
        {
            "range": [
                {
                    "introduced": "2.13.0"
                },
                {
                    "fixed": "2.14.0"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StringRangeExpression"
        },
        {
            "range": [
                {
                    "fixed": "180783930de91876bc0d601f826a1f2956057291"
                }
            ],
            "source": "REFERENCES_COMMIT"
        },
        {
            "original_tag": "2.14.0",
            "range": [
                {
                    "fixed": "c6fe464b356ff4b1ebc9ba62172d331a40aa27df"
                }
            ],
            "source": "REFERENCES_TAG"
        }
    ]
}

Affected versions

2.*

2.13.0

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-102272.json"