FFmpeg 7.1 through 9.0.2 Heap Out-of-Bounds Write via Vulkan Slice Buffer Sizing
Affects FFmpeg 7.1 through 9.0.2 when decoding uses the Vulkan hwaccel path. No fixed version is listed in the checked facts.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- No fix listed
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. FFmpeg 7.1 through 9.0.2 (affected range) Vulkan hwaccel decoding path is used
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 17/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
FFmpeg versions 7.1 through 9.0.2 contain a heap out-of-bounds write in the Vulkan hardware decoding path that an attacker can trigger locally, without logging in, if a user is tricked into opening a crafted media stream. Exploitation could let an attacker corrupt memory and potentially impact the confidentiality, integrity, and availability of the affected system.
Read the original description
FFmpeg 7.1 through 9.0.2 contains an integer overflow in ff_vk_decode_add_slice() in libavcodec/vulkan_decode.c that miscalculates the Vulkan hwaccel bitstream buffer size. Attackers can supply a crafted stream with over 2 GiB of slice data per frame, causing memcpy() to write past a smaller pooled host-mapped buffer.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure5/25Specific setups only
- Reach?/20Unknown. No tracked technology or package matched
- Severity7.3/10CVSS 7.3
- No patch5/5No patch listed yet
What would change the score
- Would score about 67 if added to CISA KEV
- Would score about 62 if CISA's SSVC rates exploitation active
- Would score about 27 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
FFmpeg 7.1 through 9.0.2 (affected range) Vulkan hwaccel decoding path is usedWorkaround: The checked facts give no official workaround. The bug is tied to the Vulkan hwaccel decoding path, so limiting or avoiding that path is the only option the facts support.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- FFmpeg FFmpeg
From 7.1 · through 9.0.2
Evidence 4
- Report
- Repository
- Repository
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-125249
Is CVE-2026-125249 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
FFmpeg miscalculates the size of the Vulkan hwaccel bitstream buffer. When a crafted stream carries over 2 GiB of slice data per frame, memcpy() writes past a smaller pooled host-mapped buffer, causing a heap out-of-bounds write.Source: vulncheck.com
Which versions are affected by CVE-2026-125249?
FFmpeg: from 7.1 through 9.0.2.Source: cve.now feed data
Am I affected, and how do I check?
FFmpeg 7.1 through 9.0.2 are in the affected range, but only when the Vulkan hwaccel decoding path is used. To check a version, run ffmpeg -version; to check the decoding path, look for Vulkan hardware acceleration in the command or settings used for decoding.Source: vulncheck.com
How do I fix CVE-2026-125249?
The checked facts list no fixed version, so no specific upgrade target can be given. Check the FFmpeg project for a release that names this fix and move to it when available.Source: vulncheck.com
What if there's no patch?
The checked facts give no official workaround. The bug is tied to the Vulkan hwaccel decoding path, so limiting or avoiding that path is the only option the facts support.Source: vulncheck.com