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Medium 4.8Published Sep 28, 2026

CVE-2026-102269PyJWT: Non-canonical signature segments enable raw-token revocation bypass

Updated under an hour ago ()

Does this affect you?

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

No exploitation reported and no EPSS estimate yet.

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT signature segment is affected because signature segment decoding accepts characters outside the canonical Base64URL representation. This occurs when non-Base64URL characters are appended to a valid compact JWS signature segment. As a result, base64url_decode produces the same signature bytes for different serialized segments. Consequently, raw-token revocation checks can fail to recognize an equivalent modified token. This issue is fixed in version 2.14.0.

CVSS
4.8 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Weakness (CWE)
CWE-180
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

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

  • x-refsource-confirm, exploit, mitigation, vendor-advisory
  • x-refsource-misc, patch
  • x-refsource-misc, product, release-notes

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.

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