CVE-2021-44227 — mailman
HIGHCVE-2021-44227 is a high-severity (CVSS 8.8) Cross-Site Request Forgery (CSRF) vulnerability in mailman. A fix is available for mailman — see the affected versions and patch details below.
Cross Site Request Forgery in mailman
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-44227 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
mailmanReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
In GNU Mailman before 2.1.38, a list member or moderator can get a CSRF token and craft an admin request (using that token) to set a new admin password or make other changes.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | mailman | all versions | 2.1.38pip install --upgrade 'mailman==2.1.38' |
Affected Products
debian linuxdebianmailmangnuDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mailman, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mailman to 2.1.38 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-44227 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.Source: Red Hat security advisory for CVE-2021-44227 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 7 | mailman-3:2.1.15-30.el7_9.2 | RHSA-2021:4913 |
| Red Hat Enterprise Linux 8 | mailman:2.1-8050020211129071856.aa3ced04 | RHSA-2021:4916 |
| Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions | mailman:2.1-8010020211206073347.656b880e | RHSA-2021:5081 |
| Red Hat Enterprise Linux 8.2 Extended Update Support | mailman:2.1-8020020211206073633.c3a0935b | RHSA-2021:5080 |
| Red Hat Enterprise Linux 8.4 Extended Update Support | mailman:2.1-8040020211129072238.70584597 | RHSA-2021:4915 |
Frequently Asked Questions
Is CVE-2021-44227 in your dependencies?
Find it across PyPI, including transitive dependencies.