CVE-2025-27607
Python JSON Logger has a Potential RCE via missing `msgspec-python313-pre` dependency
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Python JSON Logger has a Potential RCE via missing `msgspec-python313-pre` dependency
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.
- Record
CVE-2025-27607- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-829
- Updated
- 2026-11-02
EUVDEUVD-2025-7799
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.
- Record
EUVD-2025-7799- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-27607- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-829
- Updated
- 2026-11-02
OSV
Python JSON Logger has a Potential RCE via missing `msgspec-python313-pre` dependency
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.
- Record
CVE-2025-27607- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-829
- Updated
- 2026-11-02
OSVUBUNTU-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.
- Record
UBUNTU-CVE-2025-27607- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
python-pythonjsonloggerUbuntu:20.04:LTS |
All versions, plus listed versions 0.1.11-2 |
None known |
python-pythonjsonloggerUbuntu:22.04:LTS |
All versions, plus listed versions 2.0.1-12.0.1-2 |
None known |
python-pythonjsonloggerUbuntu:24.04:LTS |
All versions, plus listed versions 2.0.1-32.0.1-4 |
None known |
python-pythonjsonloggerUbuntu:25.10 |
All versions, plus listed versions 3.2.1-13.3.0-1 |
None known |
python-pythonjsonloggerUbuntu:26.10 |
All versions, plus listed versions 3.3.0-1 |
None known |
python-pythonjsonloggerUbuntu:26.04:LTS |
All versions, plus listed versions 3.3.0-1 |
None known |
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | Barsug/msgspec-python313-pre | 2025-03-14 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-27607 is a high vulnerability (CVSS 8.8) in Nhairs Python-json-logger, published March 7, 2025. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 1.61%, the 76th percentile. No source names a fixed version.
References
github.com/nhairs/python-json-logger/security/advisories/GHSA-wmxh-pxcx-9w24
nvd.nist.gov/vuln/detail/CVE-2025-27607
ubuntu.com/security/CVE-2025-27607
cve.org/CVERecord?id=CVE-2025-27607