# CVE-2026-34089: Memory leak in Scribunto causes runJobs.php to run out of memory

> A memory leak in Scribunto causes runJobs.php to exhaust memory, leading to denial of service for MediaWiki installations.

- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 May 2026
- **Updated:** 11 May 2026
- **Also known as:** GHSA-mcf6-vhp9-g7jr, UBUNTU-CVE-2026-34089

## What is CVE-2026-34089?

CVE-2026-34089 is a low-severity denial of service vulnerability in Wikimedia Foundation Scribunto, published on 11 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Vulnerability in Wikimedia Foundation Scribunto.

This issue affects Scribunto: from 1.45.0 before 1.45.2.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime), CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-34089?

It affects 1 product.


Products: Wikimedia Scribunto.

## How do I fix CVE-2026-34089?

No fix has been published for CVE-2026-34089 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-34089 being exploited?

There is no known exploitation of CVE-2026-34089 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34089 and fix it if it is affected.

What it is: CVE-2026-34089 is a low-severity denial of service vulnerability in Wikimedia Foundation Scribunto, published on 11 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-34089 in the wild and no public exploit code.

Affected product: Wikimedia Foundation Scribunto. No package-level version data is available, so check the vendor advisory linked from the reference page.

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/CVE-2026-34089/ (Markdown: https://insights.sbomify.com/CVE-2026-34089/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34089
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34089
- OSV: https://osv.dev/vulnerability/CVE-2026-34089

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34089/
Summaries are generated and may contain mistakes; the official description above is the record.