pip has an interpretation conflict due to handling both concatenated tar and ZIP files as ZIP files
pip handles concatenated tar and ZIP files as ZIP files regardless of filename or whether a file is both a tar and ZIP file. This behavior could result in confusing installation behavior, such as installing "incorrect" files according to the filename of the archive. New behavior only proceeds with installation if the file identifies uniquely as a ZIP or tar archive, not as both.
02 / AFFECTED SOFTWARE
Affected packages
154 explicit affected versions
154 explicit affected versions
25 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
pip handles concatenated tar and ZIP files as ZIP files regardless of filename or whether a file is both a tar and ZIP file. This behavior could result in confusing installation behavior, such as installing "incorrect" files according to the filename of the archive. New behavior only proceeds with installation if the file identifies uniquely as a ZIP or tar archive, not as both.
pip handles concatenated tar and ZIP files as ZIP files regardless of filename or whether a file is both a tar and ZIP file. This behavior could result in confusing installation behavior, such as installing "incorrect" files according to the filename of the archive. New behavior only proceeds with installation if the file identifies uniquely as a ZIP or tar archive, not as both.
pip handles concatenated tar and ZIP files as ZIP files regardless of filename or whether a file is both a tar and ZIP file. This behavior could result in confusing installation behavior, such as installing "incorrect" files according to the filename of the archive. New behavior only proceeds with installation if the file identifies uniquely as a ZIP or tar archive, not as both.
05 / REFERENCES
Further evidence
- http://www.openwall.com/lists/oss-security/2026/04/20/8
- https://github.com/pypa/pip
- https://github.com/pypa/pip/issues/13867
- https://github.com/pypa/pip/pull/13870
- https://mail.python.org/archives/list/[email protected]/thread/QAJ5JIVWWCAJ4EZL2FP5MOOW35JS7LRJ
- https://nvd.nist.gov/vuln/detail/CVE-2026-3219
- https://github.com/advisories/GHSA-58qw-9mgm-455v
- https://pypi.org/project/pip
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3219.json
- https://mail.python.org/archives/list/[email protected]/thread/QAJ5JIVWWCAJ4EZL2FP5MOOW35JS7LRJ/