Buffer overflow in Saitoha Libsixel
CVE-2026-33020
libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow which leads to a heap buffer overflow via sixel_frame_convert_to_rgb888() in frame.c, where allocation size…
Vulnerability class: Buffer Overflow
EPSS: 0.000 (6.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H.
Affected products
- Saitoha Libsixel — versions < 1.8.7-r1
Weakness classification (CWE)
References
- https://github.com/saitoha/libsixel/security/advisories/GHSA-2xgm-4x47-2x2p (x_refsource_CONFIRM)
- https://github.com/saitoha/libsixel/releases/tag/v1.8.7-r1 (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-33020?
- CVE-2026-33020 is a high-severity vulnerability in Saitoha Libsixel, classified under Heap-based Buffer Overflow. CVSS score: 7.1/10. Published 2026-04-14.
- How severe is CVE-2026-33020?
- High severity. CVSS v3 base score is 7.1 out of 10.