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Fencer Vulns
medium 6.1

CVE-2021-43331 json

In GNU Mailman before 2.1.36, a crafted URL to the Cgi/options.py user options page can execute arbitrary JavaScript for XSS.

published 2021-11-12 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-30269

cvss
6.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 72%
public exploits
0
none known

Summary

In GNU Mailman before 2.1.36, a crafted URL to the Cgi/options.py user options page can execute arbitrary JavaScript for XSS.

Patch / fix

  • gnu mailman 2.1.36
  • mailman Ubuntu 18.04 LTS 1:2.1.26-1ubuntu0.5
  • mailman Ubuntu Pro 16.04 LTS 1:2.1.20-1ubuntu0.6+esm2
  • mailman Ubuntu Pro 20.04 LTS 1:2.1.29-1ubuntu3.1+esm1

ubuntu advisories UBUNTU-CVE-2021-43331

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • mailman SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +10 more 2.1.17-3.26.1

suse advisories SUSE-SU-2022:1886-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-43331 updated cvss 6.1

mailman: XSS in Cgi/options.py via crafted URL

  • Red Hat Enterprise Linux 6 mailman Red Hat Enterprise Linux 7 mailman
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 mailman
    affected: no fix planned “Will not fix”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.38% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.