OSV-2025-855 Use-of-uninitialized-value in AlphaReplace_SSE2
Not scored
Published
Check this codebase for OSV-2025-855 and fix it if it is affected.
What it is: OSV-2025-855 is a vulnerability in libwebp, published on 24 Oct 2025.
Exploitation: There is no known exploitation of OSV-2025-855 in the wild and no public exploit code.
Affected packages and fixed versions:
- libwebp (OSS-Fuzz): affected all versions; no fix listed
Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/OSV-2025-855/ (Markdown: https://insights.sbomify.com/OSV-2025-855/index.md)
A use-of-uninitialized-value bug in the WebP library's AlphaReplace_SSE2 function can cause a crash during image encoding.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- None listed
What is OSV-2025-855?
OSV-2025-855 is a vulnerability in libwebp, published on 24 Oct 2025.
Official description
OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=454314139
Crash type: Use-of-uninitialized-value
Crash state:
AlphaReplace_SSE2
WebPReplaceTransparentPixels
WebPEncode
Which versions are affected by OSV-2025-855?
1 open source package ship an affected version, including libwebp.
| Package | Affected | Fixed in |
|---|---|---|
libwebp OSS-Fuzz | All versions | None |
How do I fix OSV-2025-855?
No fix has been published for OSV-2025-855 yet. Limit exposure of the affected software until one is available.
Is OSV-2025-855 being exploited?
There is no known exploitation of OSV-2025-855 in the wild and no public exploit code.