CVE-2026-33165CWE-787

heap out-of-bounds write in libde265 1.0.16

Medium · published March 20, 2026

CVSS v3.1
5.5
EPSS
0%
Percentile
8.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
5.5 · MEDIUM
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00196 · 8.8th percentile
Weakness
CWE-787 · Out-of-bounds Write
Published
2026-03-20T20:32Z
EPSS history
Timeline
  • 20 MAR 20:32Z
    heap out-of-bounds write in libde265 1.0.16
    cvelistv5