CVE-2026-33165 | heap out-of-bounds write in libde265 1.0.16

Exp

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.

Published: 2026-03-20 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-33165 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.23%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-33165

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-33165

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.01% 0.23% +0.22%
2 2026-03-21 — 0.01% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-33165

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]
5.0 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.3 3.6 [email protected]

Weakness enumeration for CVE-2026-33165

OS Trackers for CVE-2026-33165

vendor priority summary link
alpine — CVE-2026-33165: 1 source package rows (libde265); 25 state rows across 6 repos (3.19-main, 3.20-main, 3.21-main, 3.22-main, 3.23-main, edge-main); fixed 0, open 25. https://security.alpinelinux.org/vuln/CVE-2026-33165
debian not yet assigned CVE-2026-33165 not yet assigned priority: Debian including 1 source packages (libde265), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. https://security-tracker.debian.org/tracker/CVE-2026-33165
ubuntu medium CVE-2026-33165 medium priority: Ubuntu including 1 source packages (libde265), 7 status rows across 7 suites (bionic, focal, jammy, noble, questing, upstream, xenial): needs-triage 7. https://ubuntu.com/security/CVE-2026-33165

Affected software / configurations for CVE-2026-33165

Vendor Product Version Raw CPE
struktur libde265 < 1.0.17 cpe:2.3:a:struktur:libde265:*:*:*:*:*:*:*:*

References for CVE-2026-33165

cvelogic Threat Intelligence