OSV-2026-53 Heap-use-after-free in graph::LigatureSubstFormat1::shrink
Not scored
Published
Check this codebase for OSV-2026-53 and fix it if it is affected.
What it is: OSV-2026-53 is an use after free vulnerability in harfbuzz, published on 15 Jan 2026.
Exploitation: There is no known exploitation of OSV-2026-53 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-2026-53/ (Markdown: https://insights.sbomify.com/OSV-2026-53/index.md)
A heap-use-after-free in HarfBuzz allows attackers to cause crashes or potentially execute code via crafted font data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- None listed
What is OSV-2026-53?
OSV-2026-53 is an use after free vulnerability in harfbuzz, published on 15 Jan 2026.
Official description
OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=475607265
Crash type: Heap-use-after-free READ 8
Crash state:
graph::LigatureSubstFormat1::shrink
graph::LigatureSubstFormat1::split_context_t::shrink
hb_vector_t<unsigned int, false> graph::actuate_subtable_split<graph::LigatureSu
Which versions are affected by OSV-2026-53?
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-2026-53?
No fix has been published for OSV-2026-53 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-2026-53 being exploited?
There is no known exploitation of OSV-2026-53 in the wild and no public exploit code.