CVE-2025-27607
Python JSON Logger has a Potential RCE via missing `msgspec-python313-pre` dependency
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 3.3.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- 1 proof of concept on GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: poc
- Automatable: no
- Technical impact: total
Summary
Python JSON Logger is a JSON Formatter for Python Logging. 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]). This issue has been resolved with 3.3.0.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- nhairs python-json-logger
From 3.2.0 · fixed in 3.3.0