CVE-2026-44638

Low

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.

SeverityLow

CVSS2.5

Exploit probability—

ProductSaitoha Libsixel

PublishedMay 14, 2026

First seenMay 14, 2026

Weakness typeCWE-476NULL pointer dereference CWE-690CWE-690

How to fix

Update

saitoha libsixel1.8.7-r2 or later

Affected products

Product	Affected versions	Fixed in
saitoha libsixel	1.0.0 ≤ v < 1.8.7-r2	1.8.7-r2

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