OSV-2026-623 Use-of-uninitialized-value in Mat_PrintNumber
Not scored
Published
Check this codebase for OSV-2026-623 and fix it if it is affected.
What it is: OSV-2026-623 is a vulnerability in matio, published on 25 Apr 2026.
Exploitation: There is no known exploitation of OSV-2026-623 in the wild and no public exploit code.
Affected packages and fixed versions:
- matio (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-2026-623/ (Markdown: https://insights.sbomify.com/OSV-2026-623/index.md)
An attacker can cause a denial of service via a use-of-uninitialized-value bug in the Mat_PrintNumber function of the MATLAB file library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- None listed
What is OSV-2026-623?
OSV-2026-623 is a vulnerability in matio, published on 25 Apr 2026.
Official description
OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=505903317
Crash type: Use-of-uninitialized-value
Crash state:
Mat_PrintNumber
Mat_PrintData
Mat_VarPrint
Which versions are affected by OSV-2026-623?
1 open source package ship an affected version, including matio.
| Package | Affected | Fixed in |
|---|---|---|
matio OSS-Fuzz | All versions | None |
How do I fix OSV-2026-623?
No fix has been published for OSV-2026-623 yet. Limit exposure of the affected software until one is available.
Is OSV-2026-623 being exploited?
There is no known exploitation of OSV-2026-623 in the wild and no public exploit code.