CVE catalog

CVE-2020-26148

md4c: CVE-2020-26148

Severity: Medium
Published: Sep 30, 2020, 6:15:00 PM UTC
Source: [NVD] · [CVE record]
EPSS: 1.42% · Oct 25, 2026

md_push_block_bytes in md4c.c in md4c 0.4.5 allows attackers to trigger use of uninitialized memory, and cause a denial of service (e.g., assertion failure) via a malformed Markdown document.

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	md4c	sid	`0.5.3-1`	fixed
Debian	md4c	forky	`0.5.3-1`	fixed
Debian	md4c	trixie	`0.5.2-2`	fixed
Debian	md4c	bookworm	`0.4.8-1`	fixed
Ubuntu	md4c	20.04	`0.3.4-1`	vulnerable
Ubuntu	md4c	20.04	`0.4.1-1`	vulnerable
Ubuntu	md4c	20.04	`0.4.2-1`	vulnerable
Ubuntu	md4c	20.04	`0.4.3-1`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	md4c	source	sid	`0.4.5-2`	not yet assigned	Not reported	[971396]
Debian	md4c	source	forky	`0.4.5-2`	not yet assigned	Not reported	[971396]
Debian	md4c	source	trixie	`0.4.5-2`	not yet assigned	Not reported	[971396]
Debian	md4c	source	bookworm	`0.4.5-2`	not yet assigned	Not reported	[971396]

[Debian bug #971396]

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[libmd4c0]Fixed
Source package: [md4c]
Details (2)
- 0.4.8-1 · amd64 · bookworm
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · bookworm; dsa · md4c · debian · 12
- 0.4.8-1 · arm64 · bookworm
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · bookworm; dsa · md4c · debian · 12
[libmd4c-dev]Fixed
Source package: [md4c]
Details (2)
- 0.4.8-1 · amd64 · bookworm
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · bookworm; dsa · md4c · debian · 12
- 0.4.8-1 · arm64 · bookworm
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · bookworm; dsa · md4c · debian · 12
[libmd4c-html0]Fixed
Source package: [md4c]
Details (2)
- 0.4.8-1 · amd64 · bookworm
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · bookworm; dsa · md4c · debian · 12
- 0.4.8-1 · arm64 · bookworm
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · bookworm; dsa · md4c · debian · 12
[libmd4c-html0-dev]Fixed
Source package: [md4c]
Details (2)
- 0.4.8-1 · amd64 · bookworm
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · bookworm; dsa · md4c · debian · 12
- 0.4.8-1 · arm64 · bookworm
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · bookworm; dsa · md4c · debian · 12

[Debian 13 (Trixie)]

[libmd4c0]Fixed
Source package: [md4c]
Details (2)
- 0.5.2-2+b1 · amd64 · trixie
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · 13
- 0.5.2-2+b1 · arm64 · trixie
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · 13
[libmd4c-dev]Fixed
Source package: [md4c]
Details (2)
- 0.5.2-2+b1 · amd64 · trixie
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · 13
- 0.5.2-2+b1 · arm64 · trixie
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · 13
[libmd4c-html0]Fixed
Source package: [md4c]
Details (2)
- 0.5.2-2+b1 · amd64 · trixie
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · 13
- 0.5.2-2+b1 · arm64 · trixie
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · 13
[libmd4c-html0-dev]Fixed
Source package: [md4c]
Details (2)
- 0.5.2-2+b1 · amd64 · trixie
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · 13
- 0.5.2-2+b1 · arm64 · trixie
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · 13
[md2html]Fixed
Source package: [md4c]
Details (2)
- 0.5.2-2+b1 · amd64 · trixie
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · 13
- 0.5.2-2+b1 · arm64 · trixie
  Fixed · Fixed: 0.4.5-2
  dsa · md4c · debian · 13

Observed: Oct 23, 2026, 5:50:01 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database]