DEBIAN-CVE-2026-33018
- Source
- https://security-tracker.debian.org/tracker/CVE-2026-33018
- Import Source
- https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33018.json
- JSON Data
- https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-33018
- Upstream
- Published
- 2026-04-14T22:16:30Z
- Modified
- 2026-09-14T17:03:08Z
- Severity
-
- 7.0 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H CVSS Calculator
- Summary
- [none]
- Details
-
libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain a Use-After-Free vulnerability via the load_gif() function in fromgif.c, where a single sixel_frame_t object is reused across all frames of an animated GIF and gif_init_frame() unconditionally frees and reallocates frame->pixels between frames without consulting the object's reference count. Because the public API explicitly provides sixel_frame_ref() to retain a frame and sixel_frame_get_pixels() to access the raw pixel buffer, a callback following this documented usage pattern will hold a dangling pointer after the second frame is decoded, resulting in a heap use-after-free confirmed by ASAN. Any application using sixel_helper_load_image_file() with a multi-frame callback to process user-supplied animated GIFs is affected, with a reliable crash as the minimum impact and potential for code execution. This issue has been fixed in version 1.8.7-r1.
- References
Affected packages
Debian:12 / libsixel
Package
- Name
- libsixel
- Purl
- pkg:deb/debian/libsixel?arch=source&distro=bookworm
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affected
Debian:13 / libsixel
Package
- Name
- libsixel
- Purl
- pkg:deb/debian/libsixel?arch=source&distro=trixie
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affected
Debian:14 / libsixel
Package
- Name
- libsixel
- Purl
- pkg:deb/debian/libsixel?arch=source&distro=forky