CVE-2026-102270
PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.
MEDIUM 4.4
At a glance
- Source
- NVD
- EPSS
- EPSS 0.25 % · percentile 16 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT is_pem_format is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matching END marker. As a result, is_pem_format performs unbounded backtracking while searching for a PEM end marker. Consequently, an attacker can cause intensive CPU consumption. This issue is fixed in version 2.14.0.
Weaknesses (CWE)
- CWE-1333 — Inefficient Regular Expression Complexity (ReDoS)
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 4.4 | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
| CVSS 3.1 | MEDIUM 4.4 | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | MEDIUM 4.9 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
Advisories
- GHSA-jwrc-g2q2-pq5p — PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.
- PYSEC-2026-4148 — PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.
European references
- ENISA EUVD · EUVD-2026-88537
- GCVE · GCVE-0-2026-102270
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1249 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:*< 2.14.0
Affected products
| Product | Versions |
|---|---|
| jpadilla · pyjwt | affected < 2.14.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |