CVE-2025-27607: Python JSON Logger is a JSON Formatter for Python Logging

Q: How do I fix CVE-2025-27607?

python json logger: upgrade to 3.3.0. Exact commands for each OS are on this page.

Q: Is CVE-2025-27607 being exploited?

CVE-2025-27607 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2025-27607 affect?

CVE-2025-27607 affects python json logger. Severity is high (CVSS 8.8). 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

Q: How urgent is CVE-2025-27607?

Priority 55/100. High severity; Public exploit reference

This month

HIGH 8.8UPGRADE

CVE-2025-27607 is a high-severity flaw (CVSS 8.8) affecting python json logger. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 i

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.6% (top 24%)
CISA exploited list	No
Weakness	CWE-829
Published	2025-03-07
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: nhairs

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-03-07 17:15 UTCPublished CVE record published
2026-06-17 09:03 UTCUpdated Record last modified

nhairs python json logger UPGRADE

Affected: < 3.3.0

Fixed in: 3.3.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy python-json-logger || rpm -q python-json-logger || python-json-logger --version

2. UPGRADE to 3.3.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade python-json-logger

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade python-json-logger

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-2025-27607?

python json logger: upgrade to 3.3.0. Exact commands for each OS are on this page.

Is CVE-2025-27607 being exploited?

CVE-2025-27607 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-2025-27607 affect?

CVE-2025-27607 affects python json logger. Severity is high (CVSS 8.8). 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

How urgent is CVE-2025-27607?

Priority 55/100. High severity; Public exploit reference

Software pages

Python vulnerabilities

References

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