CVE-2026-44638
libsixel: NULL pointer dereference
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.
CVSS Vector Breakdown
AV:LAttack VectorAC:HAttack ComplexityPR:NPrivileges RequiredUI:RUser InteractionS:UScopeC:NConfidentialityI:NIntegrityA:LAvailabilityWeaknesses
Affected Products
Attack Graph
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Exploitability
MITRE ATT&CK
2 techniquesReferences
Timeline
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