Buffer overflow in Struktur Libde265
CVE-2026-33165
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.002 (15.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 15.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001
Affected products
- Struktur Libde265
- Strukturag Libde265 — versions < 1.0.17
Weakness classification (CWE)
References
- github.com/strukturag/libde265/security/advisories/GHSA-653q-9f73-8hvg (Exploit, Patch, Vendor Advisory)
- github.com/strukturag/libde265/commit/c7891e412106130b83f8e8ea8b7f907e9449b658 (Patch)
- github.com/strukturag/libde265/releases/tag/v1.0.17 (Release Notes)
Frequently asked questions
- What is CVE-2026-33165?
- CVE-2026-33165 is a medium-severity vulnerability in Struktur Libde265, classified under Out-of-bounds Write. CVSS score: 5.5/10. Published 2026-03-20.
- How severe is CVE-2026-33165?
- Medium severity. CVSS v3 base score is 5.5 out of 10.