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CRITICAL

CVE-2026-82331

CVSS v3

9.8

CRITICAL

EPSS Score

0.4 %

exploit probability, as of 2026-09-28

CISA KEV

No

known exploited

Exploitation

—

SSVC status

Description

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 tarb

Technical details

Published
2026-09-23
Last Modified
2026-09-23

Frequently asked questions

What is CVE-2026-82331?

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 tarb

Is CVE-2026-82331 actively exploited?

Active exploitation of CVE-2026-82331 has not been confirmed. Its EPSS score was 0.4% on 2026-09-28, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-82331?

CVE-2026-82331 has a CVSS v3 base score of 9.8 (CRITICAL severity).

Is CVE-2026-82331 affecting your environment?

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