OSV-2026-98 Heap-buffer-overflow in hostname_issubdomain
Not scored
Published
Check this codebase for OSV-2026-98 and fix it if it is affected.
What it is: OSV-2026-98 is a memory corruption vulnerability in dnsmasq, published on 21 Jan 2026.
Exploitation: There is no known exploitation of OSV-2026-98 in the wild and no public exploit code.
Affected packages and fixed versions:
- dnsmasq (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-2026-98/ (Markdown: https://insights.sbomify.com/OSV-2026-98/index.md)
A heap-buffer-overflow in hostname_issubdomain can cause a crash, potentially leading to denial of service in applications using this library.
- Exploited in the wild
- Not known
- Login needed
- Not stated
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- None listed
What is OSV-2026-98?
OSV-2026-98 is a memory corruption vulnerability in dnsmasq, published on 21 Jan 2026.
Official description
OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=476539622
Crash type: Heap-buffer-overflow READ 1
Crash state:
hostname_issubdomain
fuzz_util.c
Which versions are affected by OSV-2026-98?
1 open source package ship an affected version, including dnsmasq.
| Package | Affected | Fixed in |
|---|---|---|
dnsmasq OSS-Fuzz | All versions | None |
How do I fix OSV-2026-98?
No fix has been published for OSV-2026-98 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is OSV-2026-98 being exploited?
There is no known exploitation of OSV-2026-98 in the wild and no public exploit code.