CVE-2026-44638
On allocation failure, the function continues and writes through a NULL pointer, crashing the process.
Does this matter?
Lower severity and a low EPSS score (0.13%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 2.5 LOWCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
- EPSS
- 0.13% probability · 3th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-476, CWE-690
- Affected
- saitoha/libsixel
- Source
- security-advisories@github.com
References
- https://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3wExploit, Vendor Advisory
- https://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3wExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.