CVE-2025-27607

CVE-2025-27607 is a high-severity vulnerability in Nhairs Python Json Logger with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-829.

Key facts

Description

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.

Frequently asked questions

What is CVE-2025-27607?
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.
How severe is CVE-2025-27607?
CVE-2025-27607 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-27607 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-27607?
CVE-2025-27607 affects Nhairs Python Json Logger. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-27607?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-27607 have an EU (EUVD) identifier?
Yes. CVE-2025-27607 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-7799.
When was CVE-2025-27607 published?
CVE-2025-27607 was published on 2025-03-07 and last updated on 2026-06-17.

References

Affected products (1)

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