High 7.4Published Sep 28, 2026

CVE-2026-102271PyJWT: Public keys in DER form are accepted as HMAC secrets, bypassing the CVE-2022-29217 guard

Updated under an hour ago (2026-10-19 09:50 UTC)

Does this affect you?

It affects jpadilla pyjwt and 1 other product. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.18%, higher than 7% of scored CVEs.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for jpadilla pyjwt

Exploited in the last 30 days

PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because asymmetric-key guard relies on textual markers that are absent from DER encoding. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a DER public key as the shared verification key. As a result, PyJWT uses public DER bytes as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0.

CVSS: 7.4 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness (CWE): CWE-347
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.18% (percentile 7)
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Oct 1, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

jpadilla pyjwt jpadilla:pyjwt (from the name)	from 2.4.0, < 2.14.0	CNA record
pyjwt_project pyjwt pyjwt_project:pyjwt	from 2.4.0 before 2.14.0	NVD

References

https://github.com/jpadilla/pyjwt/security/advisories/GHSA-p4g4-x82p-q773x-refsource-confirm, exploit, patch, vendor-advisory
https://github.com/jpadilla/pyjwt/commit/2798504fa2663364573cf2d1043d8d7fef389499x-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.