GHSA-hx4r-w6wj-j8fg devalue: Residual sparse-array CPU amplification in uneval
Not scored
Published
Check this codebase for GHSA-hx4r-w6wj-j8fg and fix it if it is affected.
What it is: GHSA-hx4r-w6wj-j8fg is a denial of service vulnerability in devalue, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-hx4r-w6wj-j8fg in the wild and no public exploit code.
Affected packages and fixed versions:
- devalue (npm): affected all versions; fixed in 5.9.3
- devalue (npm): affected all versions; fixed in 5.9.3
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/GHSA-hx4r-w6wj-j8fg/ (Markdown: https://insights.sbomify.com/GHSA-hx4r-w6wj-j8fg/index.md)
An attacker can cause CPU exhaustion and event-loop blocking in applications using the devalue library by passing crafted sparse arrays to the uneval function.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-hx4r-w6wj-j8fg?
GHSA-hx4r-w6wj-j8fg is a denial of service vulnerability in devalue, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
uneval performs synchronous work proportional to a sparse array's declared length. An application that passes attacker-influenced sparse values to uneval can suffer event-loop blocking. Since attacker-controlled creation of sparse arrays is so difficult, this vulnerability is very difficult to exploit.Which versions are affected by GHSA-hx4r-w6wj-j8fg?
2 open source packages ship an affected version, including devalue.
| Package | Affected | Fixed in |
|---|---|---|
devalue npm | All versions | 5.9.3 |
devalue npm | All versions | 5.9.3 |
How do I fix GHSA-hx4r-w6wj-j8fg?
Upgrade devalue to 5.9.3 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is GHSA-hx4r-w6wj-j8fg being exploited?
There is no known exploitation of GHSA-hx4r-w6wj-j8fg in the wild and no public exploit code.