CVE-2026-65705

Heap corruption via stale flood-fill stack allocation

Published Jul 23, 2026 · Updated Jul 23, 2026

Out-of-bounds writes in FFmpeg 3.4 through 8.1.2 allow attackers to corrupt heap memory through the vf_floodfill filter. config_input() sizes the traversal stack from the initial frame, but filter_frame() pushes neighbors from a later, larger frame past that allocation. The nondefault -reinit_filter 0 setting is required; successful triggering crashes the process, while code execution depends on heap layout and hardening.

CVSS severity7.3
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds writes in FFmpeg 3.4 through 8.1.2 allow attackers to corrupt heap memory through the vf_floodfill filter. config_input() sizes the traversal stack from the initial frame, but filter_frame() pushes neighbors from a later, larger frame past that allocation. The nondefault -reinit_filter 0 setting is required; successful triggering crashes the process, while code execution depends on heap layout and hardening.

The record

CVE
CVE-2026-65705
Published
Jul 23, 2026
Updated
Jul 23, 2026
Vendor
FFmpeg
Product
FFmpeg
Classifications
CWE-131, CWE-787, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 23, 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=3.4 <=8.1.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

FFmpeg · FFmpegversion=3.4 <=8.1.2

Published CVSS scores

7.8VulnCheckCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.3VulnCheckCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-131Incorrect Calculation of Buffer Size
CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution

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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