Quick answers
- Is CVE-2026-34089 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-34089 being exploited in the wild.
- How severe is CVE-2026-34089?
- High severity, with a CVSS score of 7.5, published 11 May 2026.
- Which products and versions are affected?
- Wikimedia Foundation Scribunto 1.45.0 to 1.45.1.
- Is there a fix for CVE-2026-34089?
- A patch was published on 2026-03-19: Patch developed and referenced. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-34089 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-34089?
- Check whether you run Wikimedia Foundation Scribunto at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A memory leak exists in the Scribunto extension's LuaSandboxInterpreter due to improper management of engine objects stored in a WeakMap. A reference cycle prevents the PHP garbage collector from reclaiming memory used by engine objects, even when they are no longer needed. An attacker with permissions to create or edit Lua modules can trigger this leak by executing scripts that generate large amounts of data across multiple jobs. This leads to a PHP fatal error (memory exhaustion) in the runJobs.php background process, resulting in a denial-of-service for site maintenance tasks. The issue is resolved in version 1.45.2 by explicitly calling the engine destructor.
Affected products
- Wikimedia Foundation Scribunto 1.45.0 to 1.45.1
Timeline
- 2026-03-05: disclosed: Issue reported via Phabricator.
- 2026-03-19: patched: Patch developed and referenced.
- 2026-05-11: advisory: CVE-2026-34089 published.