OSV-2026-121 Use-of-uninitialized-value in trySubset
Not scored
Published
Check this codebase for OSV-2026-121 and fix it if it is affected.
What it is: OSV-2026-121 is a vulnerability in harfbuzz, published on 24 Jan 2026.
Exploitation: There is no known exploitation of OSV-2026-121 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-2026-121/ (Markdown: https://insights.sbomify.com/OSV-2026-121/index.md)
An attacker can cause a denial of service in the HarfBuzz font library by triggering a use-of-uninitialized-value error in the subsetter.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- None listed
What is OSV-2026-121?
OSV-2026-121 is a vulnerability in harfbuzz, published on 24 Jan 2026.
Official description
OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=477657796
Crash type: Use-of-uninitialized-value
Crash state:
trySubset
hb-subset-fuzzer.cc
Which versions are affected by OSV-2026-121?
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-2026-121?
No fix has been published for OSV-2026-121 yet. Limit exposure of the affected software until one is available.
Is OSV-2026-121 being exploited?
There is no known exploitation of OSV-2026-121 in the wild and no public exploit code.