OSV-2026-666 Heap-use-after-free in insertkey
Not scored
Published
Check this codebase for OSV-2026-666 and fix it if it is affected.
What it is: OSV-2026-666 is an use after free vulnerability in lua, published on 2 May 2026.
Exploitation: There is no known exploitation of OSV-2026-666 in the wild and no public exploit code.
Affected packages and fixed versions:
- lua (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-2026-666/ (Markdown: https://insights.sbomify.com/OSV-2026-666/index.md)
A heap-use-after-free vulnerability in the Lua interpreter's insertkey function allows attackers to potentially execute arbitrary code or cause a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not stated
- Attackable
- Not stated
- Victim action needed
- Not stated
- Fix
- None listed
What is OSV-2026-666?
OSV-2026-666 is an use after free vulnerability in lua, published on 2 May 2026.
Official description
OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=508107730
Crash type: Heap-use-after-free READ 1
Crash state:
insertkey
luaH_resize
luaH_newkey
Which versions are affected by OSV-2026-666?
1 open source package ship an affected version, including lua.
| Package | Affected | Fixed in |
|---|---|---|
lua OSS-Fuzz | All versions | None |
How do I fix OSV-2026-666?
No fix has been published for OSV-2026-666 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is OSV-2026-666 being exploited?
There is no known exploitation of OSV-2026-666 in the wild and no public exploit code.