CVE-2026-44638
libsixel: NULL pointer dereference
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Low2.5 | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L |
| NVDNVD · Analyzed | 3.1 | Low2.5 | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L |
- EPSS (exploitation in 30 days)
- 0.13% · top 97% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 2.5.
Weakness
Affected products
References (1)
- https://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3w (opens in a new tab)x_refsource_CONFIRMexploit
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-44638)Record last updated .