Skip to content
Fencer Vulns
medium 5.5

CVE-2026-33165 json

heap out-of-bounds write in libde265 1.0.16

published 2026-03-20 7 mo ago modified 2026-07-25 3 mo ago also EUVD-2026-13812 , JLSEC-2026-159

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

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.

Patch / fix

  • julia libde265_jll 1.0.18000+0
  • struktur libde265 1.0.17
  • libde265 Debian 12 1.0.11-1+deb12u3
  • libde265 Debian 13 1.0.15-1+deb13u2
  • libde265 Debian 14 1.0.18-1

debian advisories DEBIAN-CVE-2026-33165

  • libde265 Ubuntu 24.04 LTS 1.0.15-1ubuntu0.1
  • libde265 Ubuntu Pro 16.04 LTS 1.0.2-2ubuntu0.16.04.1~esm6
  • libde265 Ubuntu Pro 18.04 LTS 1.0.2-2ubuntu0.18.04.1~esm6
  • libde265 Ubuntu Pro 20.04 LTS 1.0.4-1ubuntu0.4+esm2
  • libde265 Ubuntu Pro 22.04 LTS 1.0.8-1ubuntu0.3+esm2
  • libde265 Ubuntu Pro 26.04 LTS 1.0.16-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2026-33165

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libde265 Alpine 3.24 1.0.18-r0

alpine advisories ALPINE-CVE-2026-33165

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/strukturag/libde265/security/advisories/GHSA-653q-9f73-8hvg referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 3.1 5.0 CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
OSV 3.1 5.0 CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
julia libde265_jll
<1.0.18000+0
1.0.18000+0

Affected products

  • strukturag libde265

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.