CVE catalog

CVE-2026-44638

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer

[CVE catalog]

Severity: Low · CVSS 2.5CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
Published: May 14, 2026, 7:59:29 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.13% · Oct 25, 2026

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer dereference whenever the allocation fails. The check tests the address of the output parameter (always non-NULL) instead of the value the malloc returned. On allocation failure, the function continues and writes through a NULL pointer, crashing the process. This is a denial of service against any caller of these public APIs that hits a low-memory condition. This vulnerability is fixed in 1.8.7-r2.

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	libsixel	sid	`1:1.8.7-r2-1`	fixed
Debian	libsixel	forky	`1:1.8.7-r2-1`	fixed
Debian	libsixel	trixie	`1.10.5-1`	vulnerable
Debian	libsixel	bookworm	`1.10.3-3`	vulnerable
Cpe	libsixel	Not reported	Not reported	vulnerable
Cpe	libsixel	Not reported	`1.8.7-r2`	fixed
Cpe	libsixel	Not reported	`1.8.7-r2`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	libsixel	source	sid	`1:1.8.7-r2-1`	not yet assigned	Not reported	Not reported
Debian	libsixel	source	forky	`1:1.8.7-r2-1`	not yet assigned	Not reported	Not reported
Debian	libsixel	source	trixie	`(unfixed)`	not yet assigned	Not reported	Not reported
Debian	libsixel	source	bookworm	`(unfixed)`	not yet assigned	Not reported	Not reported
Cpe	libsixel	cpe	Not reported	`1.8.7-r2`	Not reported	Not reported	Not reported
Cpe	libsixel	cpe	Not reported	`1.8.7-r2`	Not reported	NVD-CVE-2026-44638	Not reported

Notes

[trixie] libsixel: Minor issue [bookworm] libsixel: Minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[libsixel1]Affected
Source package: [libsixel]
Details (2)
- 1.10.3-3 · amd64 · bookworm
  Affected
  nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12
- 1.10.3-3 · arm64 · bookworm
  Affected
  nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12
[libsixel-bin]Affected
Source package: [libsixel]
Details (2)
- 1.10.3-3 · amd64 · bookworm
  Affected
  nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12
- 1.10.3-3 · arm64 · bookworm
  Affected
  nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12
[libsixel-dev]Affected
Source package: [libsixel]
Details (2)
- 1.10.3-3 · amd64 · bookworm
  Affected
  nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12
- 1.10.3-3 · arm64 · bookworm
  Affected
  nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12
[libsixel-examples]Affected
Source package: [libsixel]
Details (2)
- 1.10.3-3 · all · bookworm
  Affected
  nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12
- 1.10.3-3 · all · bookworm
  Affected
  nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12

[Debian 13 (Trixie)]

[libsixel1]Affected
Source package: [libsixel]
Details (2)
- 1.10.5-1 · amd64 · trixie
  Affected
  nvd · libsixel · debian · 13
- 1.10.5-1 · arm64 · trixie
  Affected
  nvd · libsixel · debian · 13
[libsixel-bin]Affected
Source package: [libsixel]
Details (2)
- 1.10.5-1 · amd64 · trixie
  Affected
  nvd · libsixel · debian · 13
- 1.10.5-1 · arm64 · trixie
  Affected
  nvd · libsixel · debian · 13
[libsixel-dev]Affected
Source package: [libsixel]
Details (2)
- 1.10.5-1 · amd64 · trixie
  Affected
  nvd · libsixel · debian · 13
- 1.10.5-1 · arm64 · trixie
  Affected
  nvd · libsixel · debian · 13
[libsixel-examples]Affected
Source package: [libsixel]
Details (2)
- 1.10.5-1 · all · trixie
  Affected
  nvd · libsixel · debian · 13
- 1.10.5-1 · all · trixie
  Affected
  nvd · libsixel · debian · 13

Observed: Oct 26, 2026, 2:25:15 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]