CVE-2026-101918

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Source
https://cve.org/CVERecord?id=CVE-2026-101918
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-101918.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-101918
Aliases
Downstream
Published
2026-09-28T20:11:55Z
Modified
2026-09-30T03:47:04Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
PyJWT: Unauthenticated RecursionError DoS in pre-verification payload parse (PyJWKClient.get_signing_key_from_jwt / verify_signature=False)
Details

PyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.get_signing_key_from_jwt is affected because payload parser catches ValueError but not RecursionError. This occurs when an attacker-controlled recursively nested payload reaches json.loads. As a result, documented PyJWT exception handling does not contain the failure. Consequently, an unauthenticated request can raise an exception that may produce an HTTP 500 response. The advisory-defined affected implementation also includes jwt/api_jwt.py, verify_signature=False. This issue is fixed in version 2.15.0.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-248"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101918.json"
}
References

Affected packages

Git / github.com/jpadilla/pyjwt

Affected ranges

Type
GIT
Repo
https://github.com/jpadilla/pyjwt
Events
Introduced
8041cb607a733a9b5fffe1e9136d55a40bcea25b
Fixed
5fde08a6cf906aa7698de2d6391d88b73006b17b
Fixed
1d41a6478e1562e68ff667fcd703356acf085f68
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "2.0.0a1"
        },
        {
            "fixed":  "2.15.0"
        }
    ],
    "source":  [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

2.*
2.0.0
2.0.0a1
2.0.0a2
2.0.1
2.1.0
2.10.0
2.10.1
2.11.0
2.12.0
2.12.1
2.13.0
2.14.0
2.2.0
2.3.0
2.4.0
2.5.0
2.6.0
2.7.0
2.8.0
2.9.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-101918.json"