CVE-2026-102270: PyJWT is a Python implementation of JSON Web Token standards

Q: How do I fix CVE-2026-102270?

pyjwt: upgrade to 2.14.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-102270 being exploited?

CVE-2026-102270 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-102270 affect?

CVE-2026-102270 affects pyjwt. Severity is medium (CVSS 4.4). 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 mar

Q: How urgent is CVE-2026-102270?

Priority 24/100. Public exploit reference

Routine

MEDIUM 4.4UPGRADE

CVE-2026-102270 is a medium-severity flaw (CVSS 4.4) affecting pyjwt. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.4 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	High
User interaction	None
EPSS exploit chance	0.2% (top 84%)
CISA exploited list	No
Weakness	CWE-1333
Published	2026-09-28
Last modified	2026-10-06

Publisher (CNA): GitHub, Inc. · Vendor: pyjwt project

Last updated 2026-10-06 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-28 21:17 UTCPublished CVE record published
2026-10-06 18:46 UTCUpdated Record last modified

pyjwt project pyjwt UPGRADE

Affected: < 2.14.0

Fixed in: 2.14.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy pyjwt || rpm -q pyjwt || pyjwt --version

2. UPGRADE to 2.14.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade pyjwt

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade pyjwt

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-102270?

pyjwt: upgrade to 2.14.0. Exact commands for each OS are on this page.

Is CVE-2026-102270 being exploited?

CVE-2026-102270 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-102270 affect?

CVE-2026-102270 affects pyjwt. Severity is medium (CVSS 4.4). 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 mar

How urgent is CVE-2026-102270?

Priority 24/100. Public exploit reference

Software pages

Python vulnerabilities

Related CVEs

CVE-2026-48526 HIGH 7.4 UPGRADE PyJWT is a JSON Web Token implementation in Python
CVE-2026-48524 LOW 3.7 UPGRADE PyJWT is a JSON Web Token implementation in Python
CVE-2026-48522 MEDIUM 4.2 UPGRADE PyJWT is a JSON Web Token implementation in Python
CVE-2026-48525 MEDIUM 5.3 UPGRADE PyJWT is a JSON Web Token implementation in Python
CVE-2026-48523 MEDIUM 5.4 UPGRADE PyJWT is a JSON Web Token implementation in Python

References

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