{"cve":"CVE-2026-82331","nvd":{"published":"2026-09-23T07:16:46.493","modified":"2026-09-23T17:58:26.570","status":"Awaiting Analysis","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.\nThe impact of this issue is mitigated by:\n\n* BuildStream projects should only use trusted sources in their elements as otherwise the build output can also not be trusted\n* Tracking a source tarball pins its SHA256 hash, which prevents MITM attacks of users that are fetching an already tracked project\n* When running on Python >= 3.12, BuildStream >= 2.3.0 already makes use of the Python `tarfile` filter functionality, which blocks the symlink escape\n\nUsers are recommended to upgrade to version 2.8.1, which fixes this issue.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-59"],"references":["https://lists.apache.org/thread/9b342631x7bvtyg0pq7zgywtl2cmy34v","http://www.openwall.com/lists/oss-security/2026/09/23/9"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-82331","score":0.00408,"percentile":0.35106,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}