Vulnerability · Published Mar 20, 2026 · Assigned by GitHub_M
CVE-2026-33165heap out-of-bounds write in libde265 1.0.16
Medium 5.5
In plain English
A medium-severity out-of-bounds write in libde265 from strukturag. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
libde265 is an open source implementation of the h.265 video codec. Prior to version 1.0.17, a crafted HEVC bitstream causes an out-of-bounds heap write confirmed by AddressSanitizer. The trigger is a stale ctb_info.log2unitSize after an SPS change where PicWidthInCtbsY and PicHeightInCtbsY stay constant but Log2CtbSizeY changes, causing set_SliceHeaderIndex to index past the allocated image metadata array and write 2 bytes past the end of a heap allocation. This issue has been patched in version 1.0.17.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.24 | libde265 | 1.0.18-r0 | ALPINE-CVE-2026-33165 |
| Debian:12 | libde265 | 1.0.11-1+deb12u3 | DEBIAN-CVE-2026-33165 |
| Debian:13 | libde265 | 1.0.15-1+deb13u2 | DEBIAN-CVE-2026-33165 |
| Debian:14 | libde265 | 1.0.18-1 | DEBIAN-CVE-2026-33165 |
| Ubuntu:24.04:LTS | libde265 | 1.0.15-1ubuntu0.1 | USN-8573-1 |
| Ubuntu:24.04:LTS | libde265 | 1.0.15-1ubuntu0.1 | UBUNTU-CVE-2026-33165 |
| Ubuntu:25.10 | libde265 | no fix listed | UBUNTU-CVE-2026-33165 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| strukturag | libde265 | < 1.0.17 |
Weakness: CWE-787 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H