An issue was discovered in views/list.py in GNU Mailman Postorius before 1.3.5. An attacker (logged into any account) can send a crafted POST request to unsubscribe any user from a mailing list, also
An issue was discovered in views/list.py in GNU Mailman Postorius before 1.3.5. An attacker (logged into any account) can send a crafted POST request to unsubscribe any user from a mailing list, also revealing whether that address was subscribed in the first place.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | postorius | < 1.3.5 | 1.3.5 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2021-40347
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=993746
- https://github.com/pypa/advisory-database/tree/main/vulns/postorius/PYSEC-2021-319.yaml
- https://gitlab.com/mailman/postorius
- https://gitlab.com/mailman/postorius/-/commit/3d880c56b58bc26b32eac0799407d74b64b7474b
- https://gitlab.com/mailman/postorius/-/issues/531
- https://gitlab.com/mailman/postorius/-/tags
- https://phabricator.wikimedia.org/T289798
- https://www.debian.org/security/2021/dsa-4970
- https://github.com/advisories/GHSA-v83x-78q3-gr2j
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N- Weakness (CWE)
CWE-284- Platform
- Python (PyPI)
- Package
postorius- Disclosed
- 10.09.2021
- Updated
- 11.10.2026 12:20
Sources and licenses
OSV / GitHub Advisory Database - GHSA-v83x-78q3-gr2j - CC BY 4.0
OSV / GitHub Advisory Database - PYSEC-2021-319 - PyPA Advisory Database; CC BY 4.0
Vulnerability history: postorius
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 09.2021 05.2026
- Without a fix
- 1
- Exploited in attacks
- 0
Severity breakdown
- High 1
- Medium 1
Disclosures per year
- 2021: 1
- 2022: 0
- 2023: 0
- 2024: 0
- 2025: 0
- 2026: 1
-
An issue was discovered in views/list.py in GNU Mailman Postorius before 1.3.5. An attacker (logged into any account) can send a crafted POST request to unsubscribe any user from a mailing list, also this entry
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