Inclusion of Functionality from Untrusted Control Sphere in python-json-logger - CVE-2025-27607

Detailed vulnerability description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to between 30 December 2024 and 4 March 2025 Python JSON Logger was vulnerable to RCE through a missing dependency. This occurred because msgspec-python313-pre was deleted by the owner leaving the name open to being claimed by a third party. If the package was claimed, it would allow them RCE on any Python JSON Logger user who installed the development dependencies on Python 3.13 (e.g. pip install python-json-logger[dev]). A remote attacker can trick the victim into opening a specially crafted data, trigger the vulnerability and execute arbitrary code on the target system.

How to mitigate CVE-2025-27607

Sources

• https://github.com/nhairs/python-json-logger/commit/2548e3a2e3cedf6bef3ee7c60c55b7c02d1af11a
• https://github.com/nhairs/python-json-logger/commit/e7761e56edb980cfab0165e32469d5fd017a5d72
• https://github.com/nhairs/python-json-logger/security/advisories/GHSA-wmxh-pxcx-9w24