CVE-2026-64831Network attack vector

Code execution via unchecked HEVC parameter count

Published Jul 22, 2026 · Updated Jul 22, 2026

Stack buffer overflow in FFmpeg 8.0 through 8.1.2 allows remote attackers to execute code via a crafted HEVC/H.265 bitstream. In vk_hevc_end_frame, an unchecked vps_num_hrd_parameters value above HEVC_MAX_SUB_LAYERS overruns stack-allocated Vulkan HEVC parameter arrays. Exploitation requires a Vulkan-enabled build to decode attacker-supplied media and can corrupt return addresses and adjacent stack frames.

CVSS severity8.7
High
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in FFmpeg 8.0 through 8.1.2 allows remote attackers to execute code via a crafted HEVC/H.265 bitstream. In vk_hevc_end_frame, an unchecked vps_num_hrd_parameters value above HEVC_MAX_SUB_LAYERS overruns stack-allocated Vulkan HEVC parameter arrays. Exploitation requires a Vulkan-enabled build to decode attacker-supplied media and can corrupt return addresses and adjacent stack frames.

The record

CVE
CVE-2026-64831
Published
Jul 22, 2026
Updated
Jul 22, 2026
Vendor
FFmpeg
Product
FFmpeg
Classifications
CWE-121, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=8.0 <=8.1.2
  2. Affected versionversion=92737390dc133daadce47dd7d2ec8ef3d9ebcbed

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FFmpeg · FFmpegversion=8.0 <=8.1.2; version=92737390dc133daadce47dd7d2ec8ef3d9ebcbed

Published CVSS scores

8.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
8.8Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.8VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1204.002User Execution: Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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