{"cve":"CVE-2026-23879","nvd":{"published":"2026-06-24T20:16:31.817","modified":"2026-10-25T22:10:00.150","status":"Deferred","description":"py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Versions 1.1.2 and below contain an an arbitrary file write vulnerability, which allows symbolic links to be recreated outside the destination directory via crafted malicious symbolic link chains. When using extractall to extract an archive, the library restores these symbolic links, linking them to arbitrary directories on the host file system. During extraction, the program only checks the link arcname within the destination directory, but ignores the combined symlink path resolution. Attackers can exploit this vulnerability by constructing malicious archives, thereby bypassing the directory boundary restrictions implemented by the extractor. Subsequent extraction of regular files through these symbolic links can result in arbitrary file writes. This vulnerability may lead to remote code execution, privilege escalation, data corruption, or denial of service. This issue has been fixed in version 1.1.3.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","score":8.0},"cwes":["CWE-59"],"references":["https://github.com/miurahr/py7zr/releases/tag/v1.1.3","https://github.com/miurahr/py7zr/security/advisories/GHSA-q6rc-2cgv-63h7","https://github.com/miurahr/py7zr/security/advisories/GHSA-q6rc-2cgv-63h7"],"products":[],"source":"nvd","synced_at":"2026-10-25T23:44:33.281319194+00:00"},"epss":{"cve":"CVE-2026-23879","score":0.00566,"percentile":0.46693,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-q6rc-2cgv-63h7","url":"https://osv.dev/vulnerability/GHSA-q6rc-2cgv-63h7","summary":"py7zr: Arbitrary File Write Vulnerability","modified":"2026-07-21T13:30:33.266395189Z","packages":[{"ecosystem":"PyPI","name":"py7zr","purl":"pkg:pypi/py7zr","ranges":["<1.1.3"],"fixed":["1.1.3"]}]},{"id":"PYSEC-2026-2974","url":"https://osv.dev/vulnerability/PYSEC-2026-2974","summary":"py7zr: Arbitrary File Write Vulnerability","modified":"2026-07-13T16:32:07.999107489Z","packages":[{"ecosystem":"PyPI","name":"py7zr","purl":"pkg:pypi/py7zr","ranges":["<1.1.3"],"fixed":["1.1.3"]}]}],"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."]}