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Ubuntu 25.10 PyJWT Important Access Check Flaw USN-8133

Linuxsecurity •LinuxSecurity Advisories • March 30, 2026

A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 25.10 - Ubuntu 24.04 LTS - Ubuntu 22.04 LTS - Ubuntu 20.04 LTS - Ubuntu 18.04 LTS - Ubuntu 16.04 LTS Summary: PyJWT could allow unintended access to network services. Software Description: - pyjwt: Python 3 implementation of JSON Web Token Details: It was discovered that PyJWT did not validate the critical header parameter, contrary to the RFC specification expectations. A remote attacker could possibly use this issue to bypass certain authentication checks and restrictions.

The problem can be corrected by updating your system to the following package versions: Ubuntu 25.10 python3-jwt 2.10.1-2ubuntu0.1 Ubuntu 24.04 LTS python3-jwt 2.7.0-1ubuntu0.1 Ubuntu 22.04 LTS python3-jwt 2.3.0-1ubuntu0.3 Ubuntu 20.04 LTS python3-jwt 1.7.1-2ubuntu2.1+esm1 Available with Ubuntu Pro Ubuntu 18.04 LTS python-jwt 1.5.3+ds1-1ubuntu0.1+esm1 Available with Ubuntu Pro python3-jwt 1.5.3+ds1-1ubuntu0.1+esm1 Available with Ubuntu Pro Ubuntu 16.04 LTS python-jwt 1.3.0-1ubuntu0.1+esm1 Available with Ubuntu Pro python3-jwt 1.3.0-1ubuntu0.1+esm1 Available with Ubuntu Pro In general, a standard system update will make all the necessary changes.

CVE-2026-32597

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This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.

Critical PyJWT Vulnerability in Multiple Ubuntu Releases A significant security flaw has been identified in the PyJWT library affecting various Ubuntu releases, including 25.10, 24.04 LTS, 22.04 LTS, 20.04 LTS, 18.04 LTS, and 16.04 LTS. The vulnerability, tracked as CVE-2026-32597, allows remote attackers to bypass authentication checks due to improper validation of the critical header parameter. This flaw contradicts the expectations set by the RFC specification, potentially exposing network services to unauthorized access. Users are urged to update their systems to the latest package versions to mitigate this risk. The vulnerability was published on March 12, 2026, and is considered critical due to its potential impact across multiple supported versions of Ubuntu. Standard system updates are recommended to address this issue. 2 sources 73

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Ubuntu 25.10 PyJWT Important Access Check Flaw USN-8133

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Extracted Entities

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