Is CVE-2026-102269 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-102269 being exploited in the wild.

How severe is CVE-2026-102269?

Medium severity, with a CVSS score of 4.8, published 28 September 2026.

Which products and versions are affected?

Jpadilla PyJWT before 2.14.0; pyjwt (PyPI) <= 2.13.0, ECOSYSTEM:introduced=0,fixed=2.14.0.

Is there a fix for CVE-2026-102269?

Yes. pyjwt (PyPI): upgrade to 2.14.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-102269 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-102269?

Check whether you run Jpadilla PyJWT or pyjwt (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-102269: PyJWT signature validation bypass via non-canonical Base64URL

Q: Is there a fix for CVE-2026-102269?

Yes. pyjwt (PyPI): upgrade to 2.14.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-102269 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-102269?

Check whether you run Jpadilla PyJWT or pyjwt (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-102269 · Severity: medium · CVSS 4.8 · Published 2026-09-28

PyJWT is a Python library for handling JSON Web Tokens, which are used to authenticate and verify secure communications in applications. A vulnerability in versions before 2.14.0 allows attackers to bypass token revocation checks by appending non-standard Base64URL characters to a valid token signature. This enables an attacker to reuse revoked tokens or forge tokens that should have been rejected, potentially leading to unauthorized access.

Technologies: Jpadilla PyJWT, pyjwt (PyPI). Vendors: Jpadilla, PyPI.

Quick answers

Is CVE-2026-102269 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-102269 being exploited in the wild.
How severe is CVE-2026-102269?: Medium severity, with a CVSS score of 4.8, published 28 September 2026.
Which products and versions are affected?: Jpadilla PyJWT before 2.14.0; pyjwt (PyPI) <= 2.13.0, ECOSYSTEM:introduced=0,fixed=2.14.0.
Is there a fix for CVE-2026-102269?: Yes. pyjwt (PyPI): upgrade to 2.14.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-102269 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-102269?: Check whether you run Jpadilla PyJWT or pyjwt (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

pyjwt (PyPI): upgrade to 2.14.0 or later
```
pip install "pyjwt>=2.14.0"
```

Technical details

The vulnerability exists in the base64url_decode function, which accepts non-canonical Base64URL characters in the signature segment of compact JWS tokens. By appending extra characters to a valid signature, an attacker can create multiple serialized representations that decode to the same bytes, bypassing raw-token revocation checks that compare serialized forms. The fix in 2.14.0 enforces strict canonical Base64URL validation.

Affected products

jpadilla PyJWT before 2.14.0

Identifiers

CVE-2026-102269
GHSA-hxm8-2xgr-2p9m
PYSEC-2026-4147

Timeline

2026-09-28: disclosed
2026-09-11: patched: Fixed in version 2.14.0

References

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