Description
GNU Mailman 2.x before 2.1.30 uses the .obj extension for scrubbed application/octet-stream MIME parts. This behavior may contribute to XSS attacks against list-archive visitors, because an HTTP reply from an archive web server may lack a MIME type, and a web browser may perform MIME sniffing, conclude that the MIME type should have been text/html, and execute JavaScript code.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 10 | mailman | 1:2.1.29-1+deb10u1 | DSA-4664-1 |
| Debian 9 | mailman | 1:2.1.23-1+deb9u5 | DSA-4664-1 |
| Debian 8 | mailman | 1:2.1.18-2+deb8u5 | DLA-2200-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | mailman | 1:2.1.29-1ubuntu3.1 | USN-5121-2 |
| Ubuntu 18.04 LTS | mailman | 1:2.1.26-1ubuntu0.1 | USN-4348-1 |
| Ubuntu 16.04 LTS | mailman | 1:2.1.20-1ubuntu0.4 | USN-4348-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | mailman | 3:2.1.29-10.module+el8.3.0+6860+8e47d84b | RHSA-2020:4667 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SLES 12 SP4 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SLES 12 SP3 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SLES 12 SP2 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SLES 12 SP1 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP4 | mailman | 2.1.15-9.6.20.1 | SUSE-SU-2020:14356-1 |
| SLES for SAP 12 SP5 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SLES for SAP 12 SP4 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SLES for SAP 12 SP3 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SLES for SAP 12 SP2 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SLES for SAP 12 SP1 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SUSE Package Hub 15 SP2 | mailman | 2.1.34-bp152.7.3.1 | openSUSE-SU-2020:1752-1 |
| SUSE OpenStack Cloud Crowbar 8 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SUSE OpenStack Cloud 8 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SUSE OpenStack Cloud 7 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | mailman | 2.1.15-9.6.20.1 | SUSE-SU-2020:14356-1 |
| SUSE HPE Helion OpenStack 8 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
| SUSE Enterprise Storage 5 | mailman | 2.1.17-3.20.1 | SUSE-SU-2020:1301-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.2 | mailman | 2.1.34-lp152.7.3.1 | openSUSE-SU-2020:1707-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | mailman | 3:2.1.29-10.module+el8.3.0+7679+d7dcf94b | ELSA-2020-4667 |
Advisories 10
- DSA-4664-1 mailman - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2200-1 mailman - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-5121-2 mailman vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-4348-1 mailman vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2020:14356-1 Security update for mailman SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:1301-1 Security update for mailman SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1707-1 Recommended update for mailman SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2020:4667 Red Hat Security Advisory: mailman:2.1 security and bug fix update Red Hat Security Advisories (RHSA) · Jan 14, 2026
- openSUSE-SU-2020:1752-1 Recommended update for mailman SUSE / openSUSE Security Updates · May 7, 2025
- ELSA-2020-4667 Moderate: mailman:2.1 security and bug fix update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 10, 2020
References
- https://www.openwall.com/lists/oss-security/2020/02/24/2
- https://www.openwall.com/lists/oss-security/2020/02/24/3
- http://bazaar.launchpad.net/~mailman-coders/mailman/2.1/view/head:/NEWS
- [oss-security] 20200424 Re: mailman 2.x: XSS via file attachments in list archives mailing-list
- DSA-4664 vendor-advisory
- [debian-lts-announce] 20200503 [SECURITY] [DLA 2200-1] mailman security update mailing-list
- USN-4348-1 vendor-advisory
- FEDORA-2020-69f2f1d987 vendor-advisory
- FEDORA-2020-20b748e81e vendor-advisory
- openSUSE-SU-2020:1707 vendor-advisory
- openSUSE-SU-2020:1752 vendor-advisory