Description
markdown2 >=1.0.1.18, fixed in 2.4.0, is affected by a regular expression denial of service vulnerability. If an attacker provides a malicious string, it can make markdown2 processing difficult or delayed for an extended period of time.
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 14 | python-markdown2 | 2.3.10-1.1 | — |
| Debian 13 | python-markdown2 | 2.3.10-1.1 | — |
| Debian 12 | python-markdown2 | 2.3.10-1.1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | python-markdown2 | No fix yet | — |
| Ubuntu 26.04 LTS | python-markdown2 | No fix yet | — |
| Ubuntu 25.10 | python-markdown2 | No fix yet | — |
| Ubuntu 24.04 LTS | python-markdown2 | No fix yet | — |
| Ubuntu 22.04 LTS | python-markdown2 | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | python-markdown2 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP2 | python-markdown2 | 2.4.0-bp152.2.4.1 | openSUSE-SU-2021:0451-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python-markdown2 | 2.4.0-2.4 | openSUSE-SU-2026:12016-1, openSUSE-SU-2024:14146-1, openSUSE-SU-2024:11237-1 |
| openSUSE Leap 15.2 | python-markdown2 | 2.4.0-lp152.2.3.1 | openSUSE-SU-2021:0429-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | markdown2 | >= 1.0.1.18, < 2.4.0 | 2.4.0 | GHSA-jr9p-r423-9m2r |
Advisories 5
- openSUSE-SU-2026:12016-1 python313-markdown2-2.5.5-1.3 on GA media SUSE / openSUSE Security Updates · Oct 5, 2026
- openSUSE-SU-2024:11237-1 python36-markdown2-2.4.0-2.4 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0451-1 Security update for python-markdown2 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0429-1 Security update for python-markdown2 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14146-1 python310-markdown2-2.4.13-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://github.com/trentm/python-markdown2/pull/387
- FEDORA-2021-77191478ad vendor-advisory
- FEDORA-2021-0337384e41 vendor-advisory
- FEDORA-2021-e235a0da4a vendor-advisory