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.
Affected products
saitoha: libsixel
References2
- github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-… ExploitVendor Advisory
- github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-… ExploitVendor Advisory
Metrics
- CVSS 3.1
-
2.5
LOW
Score source: NVD
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L - EPSS — exploit probability
- 0% percentile: 3 · as of 14 November 2026
- CWE
- CWE-476CWE-690
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