PT-2026-41034 · Saitoha · Libsixel

Published 2026-05-14 · Updated 2026-05-14 · CVE-2026-44638

NVD

CVSS v3.1

2.5

Low

Base vector

AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L

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.

Fix

NULL Pointer Dereference

Weakness Enumeration

CWE-476

CWE-690

Related Identifiers

CVE-2026-44638

Affected Products

Libsixel

References · 2

• https://nvd.nist.gov/vuln/detail/CVE-2026-44638 · Security Note
• https://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3w · Note