Infinite loop in Python - CVE-2025-8194
Published: August 7, 2025 / Updated: February 3, 2026
Vulnerability identifier: #VU113738
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-8194
CWE-ID: CWE-835
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Python.org
Affected software:
Python
Python
Detailed vulnerability description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to infinite loop in the “tarfile” module when handling tar archives with negative offsets. A remote attacker can pass a specially crafted tar archive to the application and consume all available system resources, resulting in a deadlock and a denial of service.
How to mitigate CVE-2025-8194
Install updates from vendor's website.
Sources
- https://gist.github.com/sethmlarson/1716ac5b82b73dbcbf23ad2eff8b33e1
- https://github.com/python/cpython/commit/7040aa54f14676938970e10c5f74ea93cd56aa38
- https://github.com/python/cpython/commit/cdae923ffe187d6ef916c0f665a31249619193fe
- https://github.com/python/cpython/issues/130577
- https://github.com/python/cpython/pull/137027
- https://mail.python.org/archives/list/security-announce@python.org/thread/ZULLF3IZ726XP5EY7XJ7YIN3K5MDYR2D/