CVE-2026-101918: PyJWT is a Python implementation of JSON Web Token standards

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MEDIUM 5.3REMOTEUPGRADE

CVE-2026-101918 is a medium-severity flaw (CVSS 5.3) 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. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.get_signing_key_from_jwt is affected because payload parser catches ValueError but not RecursionError. This occurs when an attacker-controlled recursively nested payload reaches json.loads. As a result, documented PyJWT exception handling does not contain the failure. Consequently, an unauthenticated request can raise an exception that may p

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 65%)
CISA exploited list	No
Weakness	CWE-248
Published	2026-09-28
Last modified	2026-10-07

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

Last updated 2026-10-07 · 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
2026-10-07 20:59 UTCUpdated Record last modified

pyjwt project pyjwt UPGRADE

Affected: >= 2.0.0 and < 2.15.0

Fixed in: 2.15.0

Safe to downgrade to: a release before 2.0.0

1. Check installed version

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

2. UPGRADE to 2.15.0 (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.

3. If no update is available yet, DOWNGRADE to a release before 2.0.0 (Debian / Ubuntu)

apt-cache madison pyjwt sudo apt install pyjwt=<VERSION_BEFORE_2.0.0> sudo apt-mark hold pyjwt

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list pyjwt sudo dnf downgrade pyjwt-<VERSION_BEFORE_2.0.0> sudo dnf versionlock add pyjwt

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Advisories and coverage

Official advisories

Amazon Linux 2023 ALAS: ALAS2023-2026-3298 (important): python-jwt 2026-10-24

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-2026-101918?

pyjwt: upgrade to 2.15.0. Exact commands for each OS are on this page.

Is CVE-2026-101918 being exploited?

CVE-2026-101918 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-2026-101918 affect?

CVE-2026-101918 affects pyjwt. Severity is medium (CVSS 5.3). PyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.get_signing_key_from_jwt is affected because payload parser catches ValueError but not RecursionError. This occurs when an attacker-c

How urgent is CVE-2026-101918?

Priority 37/100. Public exploit reference; Remotely exploitable, no login, no user action

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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