5.5

CVE-2026-33165: struktur libde265 Out-of-bounds Write

CVSS: 5.5v3.1MediumAnalyzed
AliasesALPINE-CVE-2026-33165UBUNTU-CVE-2026-33165DEBIAN-CVE-2026-33165
Published 20-03-2026Last modified 24-03-2026
Open JSON

Vulnerability summary

CVE-2026-33165 is a medium (CVSS 5.5) Out-of-bounds Write vulnerability in struktur libde265. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 8.7% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
32/100
0100
Medium · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.20%
0%100%
Low · -0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 2 · Related 1
MGASA-2026-0420USN-8573-1

Timeline

  1. 20-03-2026
    PublishedVulnerability first disclosed.
  2. 24-03-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.20%

Chance of exploitation in the next 30 days

Percentile

9%

Versus all other CVEs

30-day change

-0.04 pp

From 0.23% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.20%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Libde265

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Alpine1 product
  • libde265< 1.0.18-r0
Debian1 product
  • libde265< 1.0.11-1+deb12u3 | < 1.0.15-1+deb13u2 | < 1.0.18-1
Struktur1 product
Strukturag1 product
Ubuntu1 product
  • libde265< 1.0.2-2ubuntu0.16.04.1~esm6 | < 1.0.2-2ubuntu0.18.04.1~esm6 | < 1.0.4-1ubuntu0.4+esm2 | < 1.0.8-1ubuntu0.3+esm2 | < 1.0.15-1ubuntu0.1 | All versions (No fix recorded) | < 1.0.16-1ubuntu0.1~esm1

5 vendors · 5 products

References

8 links