Uncaught Exception in pyjwt - CVE-2026-101918

Vulnerability identifier: #VU151959

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-101918

CWE-ID: CWE-248

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to an uncaught exception in PyJWT._decode_payload when parsing a recursively nested JWT payload before signature verification. A remote attacker can submit a JWT with a deeply nested payload to cause a denial of service.

pyjwt
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Desktop 15
SUSE Manager Proxy
SUSE Manager Retail Branch Server
SUSE Manager Server
Public Cloud Module
Python 3 Module
openSUSE Leap
Ubuntu
openEuler
python3-jwt (Ubuntu package)
python-jwt (Ubuntu package)
python-jwt-help
python3-jwt
python-jwt
python311-PyJWT

Install security update from vendor's website.

pyjwt - update to 2.15.0
python3-jwt (Ubuntu package) - addressed in versions 1.3.0-1ubuntu0.1+esm4, 1.5.3+ds1-1ubuntu0.1+esm4, 1.7.1-2ubuntu2.1+esm4, 2.3.0-1ubuntu0.6, 2.7.0-1ubuntu0.4, 2.10.1-4ubuntu1.3, 2.13.0-1ubuntu1.1
python-jwt (Ubuntu package) - addressed in versions 1.3.0-1ubuntu0.1+esm4, 1.5.3+ds1-1ubuntu0.1+esm4
python-jwt-help - addressed in versions 2.3.0-12, 2.8.0-11
python3-jwt - addressed in versions 2.3.0-12, 2.8.0-11
python-jwt - addressed in versions 2.3.0-12, 2.8.0-11
python311-PyJWT - update to 2.8.0-150400.8.20.1

• https://github.com/jpadilla/pyjwt/security/advisories/GHSA-42vr-xj54-vc7v
• https://github.com/jpadilla/pyjwt/commit/5fde08a6cf906aa7698de2d6391d88b73006b17b

• Multiple vulnerabilities in pyjwt
• openEuler 22.03 LTS SP4 update for python-jwt
• openEuler 24.03 LTS SP3 update for python-jwt
• openEuler 24.03 LTS SP1 update for python-jwt
• openEuler 24.03 LTS SP4 update for python-jwt
• Ubuntu update for pyjwt
• SUSE update for python-PyJWT