Bug 2477620 (CVE-2026-44638) - CVE-2026-44638 libsixel: libsixel: Denial of Service due to NULL pointer dereference during memory allocation
Summary: CVE-2026-44638 libsixel: libsixel: Denial of Service due to NULL pointer dere...
Keywords:
Status: NEW
Alias: CVE-2026-44638
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security DevOps Team
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Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-05-14 21:01 UTC by OSIDB Bzimport
Modified: 2026-05-15 18:23 UTC (History)
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Description OSIDB Bzimport 2026-05-14 21:01:39 UTC 
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.
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