CVE-2026-102270PyJWT: ReDoS vulnerability when calling the `is_pem_format` function.
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 4.4 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-1333
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Analyzed
- Record last updated
- Sep 29, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
jpadilla pyjwt jpadilla:pyjwt (from the name) | before 2.14.0 | CNA record |
pyjwt_project pyjwt pyjwt_project:pyjwt | before 2.14.0 | NVD |
References
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-jwrc-g2q2-pq5px-refsource-confirm, exploit, patch, vendor-advisory
- https://github.com/jpadilla/pyjwt/commit/8b4e233a22206b34ec1186e912e75c0b2396ac07x-refsource-misc, patch
- https://github.com/jpadilla/pyjwt/releases/tag/2.14.0x-refsource-misc, product, release-notes
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.