CVE-2025-43921 json
GNU Mailman 2.1.39, as bundled in cPanel (and WHM), allows unauthenticated attackers to create lists via the /mailman/create endpoint.
published 2025-04-20 18 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-12590
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 41%
- public exploits
- 0
- none known
Summary
GNU Mailman 2.1.39, as bundled in cPanel (and WHM), allows unauthenticated attackers to create lists via the /mailman/create endpoint. NOTE: multiple third parties report that they are unable to reproduce this, regardless of whether cPanel or WHM is used.
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 18 mo ago
Exploit prediction
0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/0NYX-MY7H/CVE-2025-43921 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
Affected products
- GNU Mailman
Classification
- Weakness
-
- CWE-863 Incorrect Authorization
References
-
github.com
/0NYX-MY7H/CVE-2025-43921
exploit, third-party-advisory
-
code.launchpad.net
/~mailman-coders/mailman/2.1
product
- github.com /cpanel/mailman2-python3
- openwall.com /lists/oss-security/2025/04/21/6
Sources
- CVE List CVE-2025-43921
- NVD CVE-2025-43921
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