OSV-2026-962 Use-of-uninitialized-value in iup_delta_optimize
Not scored
Published
Check this codebase for OSV-2026-962 and fix it if it is affected.
What it is: OSV-2026-962 is a vulnerability in harfbuzz, published on 24 Jun 2026.
Exploitation: There is no known exploitation of OSV-2026-962 in the wild and no public exploit code.
Affected packages and fixed versions:
- harfbuzz (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-2026-962/ (Markdown: https://insights.sbomify.com/OSV-2026-962/index.md)
An attacker can cause a denial of service via a use-of-uninitialized-value bug in the IUP font library's delta optimization routine.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- None listed
What is OSV-2026-962?
OSV-2026-962 is a vulnerability in harfbuzz, published on 24 Jun 2026.
Official description
OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=526770452
Crash type: Use-of-uninitialized-value
Crash state:
iup_delta_optimize
OT::tuple_delta_t::optimize
OT::TupleVariationData<OT::NumType<true, unsigned short, 2u>>::tuple_variations_
Which versions are affected by OSV-2026-962?
1 open source package ship an affected version, including harfbuzz.
| Package | Affected | Fixed in |
|---|---|---|
harfbuzz OSS-Fuzz | All versions | None |
How do I fix OSV-2026-962?
No fix has been published for OSV-2026-962 yet. Limit exposure of the affected software until one is available.
Is OSV-2026-962 being exploited?
There is no known exploitation of OSV-2026-962 in the wild and no public exploit code.