libsixel: NULL pointer dereference_CVE-2026-44638

2.5 / 10

LOW

CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L

Description

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.

Basic Information

ID CVE-2026-44638

Source GitHub_M

Published May 14, 2026 at 19:59

Affected Product

Vendor saitoha

Product libsixel

Version >= 1.0.0, < 1.8.7-r2

Affected Versions saitoha libsixel >= 1.0.0, < 1.8.7-r2

CWE Classification

CWE-476 CWE-690

References

github.com /saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3w

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