CVSS 4.0
4.8 mediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NCVE-2026-125175 ffmpeg ffmpeg: Use of Uninitialized Resource
Medium (4.8) in ffmpeg ffmpeg. EPSS 0.1% estimated probability of exploitation activity in the next 30 days.
On this page
FFmpeg through 9.0.2 contains an information disclosure vulnerability in flashsv_decode_block() in libavcodec/flashsv.c that copies uninitialized heap memory into decoded frames when inflate output is short. Attackers can supply a crafted FLV with an FSV1 stream whose zlib block data decompresses short, then recover heap contents from the decoded or re-encoded output.
Severity
CVSS 3.1
3.3 lowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N- EPSS
- 0.1% estimated probability of exploitation activity in the next 30 days; 3rd percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: no · Technical impact: partial, assessed 2026-11-10. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-908 Use of Uninitialized Resource
- Published
- Modified
- Assigned by
- VulnCheck (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
Ask an AI about this CVE
Show the prompt
Explain CVE-2026-125175 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-125175?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-125175?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-125175 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Badge for a README or a site
An image that stays current: it is drawn from the data each time it is fetched (a host that proxies images, as GitHub does, may show its copy for a while). Markdown:
[](https://cve.bz/cve/CVE-2026-125175)
HTML:
<a href="https://cve.bz/cve/CVE-2026-125175"><img src="https://cve.bz/cve/badge/CVE-2026-125175.svg" alt="CVE-2026-125175"></a>
Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| FFmpeg | through 9.0.2 |
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Ubuntu | 26.10, Pro:16.04:LTS, Pro:18.04:LTS and 4 more | ffmpeg | no fix listed | UBUNTU-CVE-2026-125175 |
From the distributions' data via OSV.dev: Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Ubuntu.
References
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24464
- https://github.com/FFmpeg/FFmpeg
- https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/flashsv.c#L248
- https://github.com/FFmpeg/FFmpeg/commit/50d206a75b5e60261d71b25657ae04891eb60290
- https://github.com/FFmpeg/FFmpeg/commit/cfb40c912927fdd2c1186b7b6aca468422da23db
- https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-information-disclosure-via-flash-screen-video-decoder