CVE-2026-82331 (GCVE-0-2026-82331)

Vulnerability from cvelistv5 – Published: 2026-09-23 06:58 – Updated: 2026-09-23 16:08
VLAI
Title
Apache BuildStream: tar source extraction escape
Summary
Improper link resolution before file access ('link following') vulnerability in the `tar` source plugin of Apache BuildStream running on Python < 3.12 allows malicious source tarballs to write files on the host, with the privileges of the user running BuildStream, via symlinks as part of source fetching. The impact of this issue is mitigated by: * BuildStream projects should only use trusted sources in their elements as otherwise the build output can also not be trusted * Tracking a source tarball pins its SHA256 hash, which prevents MITM attacks of users that are fetching an already tracked project * When running on Python >= 3.12, BuildStream >= 2.3.0 already makes use of the Python `tarfile` filter functionality, which blocks the symlink escape Users are recommended to upgrade to version 2.8.1, which fixes this issue.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-23 14:55 UTC
CWE
  • CWE-59 - Improper link resolution before file access ('link following')
Assigner
References
Impacted products
Vendor Product Version CPE status
Apache Software Foundation Apache BuildStream Affected: 0 , ≤ 2.8.0 (semver)
Unaffected: 2.8.1 (semver)
guessed Create a notification for this product.
Credits
Gjoko Krstic of Zero Science Lab
Show details on NVD website
To clipboard 

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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