CVE-2025-8194

Tarfile infinite loop during parsing with negative member offset

There is a defect in the CPython “tarfile” module affecting the “TarFile” extraction and entry enumeration APIs. The tar implementation would process tar archives with negative offsets without error, resulting in an infinite loop and deadlock during the parsing of maliciously crafted tar archives. This vulnerability can be mitigated by including the following patch after importing the “tarfile” module:  https://gist.github.com/sethmlarson/1716ac5b82b73dbcbf23ad2eff8b33e1

We have discovered 354 live websites that are affected by CVE-2025-8194.

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Affected Software

Product  CPython
Category Programming Languages
Vulnerable Domains354 live websites (91% of CPython install base)
Vulnerable Versions
  • from 0 through 3.10.19
  • from 3.11 through 3.11.14
  • from 3.12 through 3.12.12
  • from 3.13 through 3.13.6
Vulnerable Versions Count53 versions ( 82% of all versions)


Common Weakness Enumeration

CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')



Details

  • Published - Jul 28, 2025
  • Updated - Jul 31, 2026

Credits

  • Alexander Urieles (reporter)
  • Seth Larson (coordinator)
  • Ethan Furman (remediation reviewer)
  • Steve Dower (remediation reviewer)

Website Distribution by Country

Number of websites using CVE-2025-8194
United States103 websites


Germany46 websites
Singapore25 websites
India18 websites
France16 websites
China14 websites
Switzerland10 websites
GB10 websites
Brazil9 websites
Denmark9 websites

Website Distribution by TLD

Number of websites using CVE-2025-8194
.com123 websites
.org34 websites
.dk22 websites
.net19 websites
.de13 websites
.ch8 websites
.edu6 websites
.fr6 websites
.co.uk5 websites
.cz5 websites

Vulnerable Versions

Vulnerable versions are highlighted in red

Websites affected by CVE-2025-8194

Top websites that are affected by CVE-2025-8194. Please click on the "Contact us" link to get more information.
DomainCountryRankContacts
**********.com United States**,***
*********.com Netherlands***,***
*******.***.org Germany***,***
*****.org Germany***,***
*****.*****.de Germany***,***
********.***.***.gr Greece***,***
***.********.it Italy***,***
****.*****.br Brazil*,***,***
*********.com United States*,***,***
**********.*****.*******.edu United States*,***,***
See full domain list

FAQ

CVE-2025-8194 is Loop with Unreachable Exit Condition ('Infinite Loop') in CPython
A total of 354 websites have been identified as vulnerable to CVE-2025-8194, based on global website indexing conducted by WebTechSurvey.
The CPython is affected by the CVE-2025-8194 vulnerability.
CPython versions up to 3.13.6 are vulnerable to CVE-2025-8194.
CVE-2025-8194 is resolved in version 3.13.6 of CPython.

References