CVE catalog

CVE-2021-26813

python-markdown2: CVE-2021-26813

Severity: High · CVSS 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: Mar 3, 2021, 4:15:13 PM UTC
Source: [NVD] · [CVE record]
EPSS: 2.32% · Oct 25, 2026

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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	python-markdown2	sid	`2.5.4-4`	fixed
Debian	python-markdown2	forky	`2.5.4-4`	fixed
Debian	python-markdown2	trixie	`2.4.11-1`	fixed
Debian	python-markdown2	bookworm	`2.4.1-1`	fixed
Opensuse	python-markdown2	tumbleweed	`2.5.5-1.3`	fixed
Opensuse	python-markdown2	tumbleweed	`2.4.0-2.4`	fixed
Suse	python-markdown2	package hub 15 sp2	`2.4.0-bp152.2.4.1`	fixed
Opensuse	python-markdown2	leap 15.2	`2.4.0-lp152.2.3.1`	fixed
Opensuse	python-markdown2	tumbleweed	`2.4.13-1.2`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	python-markdown2	source	sid	`2.3.10-1.1`	not yet assigned	Not reported	[984668]
Debian	python-markdown2	source	forky	`2.3.10-1.1`	not yet assigned	Not reported	[984668]
Debian	python-markdown2	source	trixie	`2.3.10-1.1`	not yet assigned	Not reported	[984668]
Debian	python-markdown2	source	bookworm	`2.3.10-1.1`	not yet assigned	Not reported	[984668]
Opensuse	python-markdown2	rpm	tumbleweed	`2.5.5-1.3`	Not reported	OPENSUSE-SU-2026:12016-1	Not reported
Opensuse	python-markdown2	rpm	tumbleweed	`2.4.0-2.4`	Not reported	OPENSUSE-SU-2024:11237-1	Not reported
Suse	python-markdown2	rpm	package hub 15 sp2	`2.4.0-bp152.2.4.1`	Not reported	OPENSUSE-SU-2021:0451-1	Not reported
Opensuse	python-markdown2	rpm	leap 15.2	`2.4.0-lp152.2.3.1`	Not reported	OPENSUSE-SU-2021:0429-1	Not reported
Opensuse	python-markdown2	rpm	tumbleweed	`2.4.13-1.2`	Not reported	OPENSUSE-SU-2024:14146-1	Not reported

[Debian bug #984668]

OpenFactory catalog packages

[openSUSE Tumbleweed]

[python313-markdown2]Unknown
Source package: [python-markdown2]
Details (1)
- 2.5.5-1.3 · noarch · tumbleweed
  Unknown · Fixed: 2.4.0-2.4, 2.4.13-1.2, 2.5.5-1.3
  Version impact unknown
  dsa · python-markdown2 · opensuse · tumbleweed
[python314-markdown2]Unknown
Source package: [python-markdown2]
Details (1)
- 2.5.5-1.3 · noarch · tumbleweed
  Unknown · Fixed: 2.4.0-2.4, 2.4.13-1.2, 2.5.5-1.3
  Version impact unknown
  dsa · python-markdown2 · opensuse · tumbleweed

[Debian 12 (Bookworm)]

[python3-markdown2]Fixed
Source package: [python-markdown2]
Details (2)
- 2.4.1-1 · all · bookworm
  Fixed · Fixed: 2.3.10-1.1
  dsa · python-markdown2 · debian · bookworm; dsa · python-markdown2 · debian · 12
- 2.4.1-1 · all · bookworm
  Fixed · Fixed: 2.3.10-1.1
  dsa · python-markdown2 · debian · bookworm; dsa · python-markdown2 · debian · 12

[Debian 13 (Trixie)]

[python3-markdown2]Fixed
Source package: [python-markdown2]
Details (2)
- 2.4.11-1 · all · trixie
  Fixed · Fixed: 2.3.10-1.1
  dsa · python-markdown2 · debian · 13
- 2.4.11-1 · all · trixie
  Fixed · Fixed: 2.3.10-1.1
  dsa · python-markdown2 · debian · 13

Observed: Oct 23, 2026, 5:55:14 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [SUSE security advisories and VEX]