CVE-2026-100242 DataTransfer depends on phpspreadsheet version vulnerable to CVE-2026-59933 (XLS/OLE memory exhaustion)
Attackers can cause denial of service via excessive memory allocation in the DataTransfer extension due to a vulnerable dependency.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-100242?
CVE-2026-100242 is a high-severity denial of service vulnerability in Wikimedia Foundation Mediawiki - DataTransfer Extension, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Dependency on Vulnerable Third-Party Component and Uncontrolled Resource Consumption vulnerability in Wikimedia Foundation Mediawiki - DataTransfer Extension allows Excessive Allocation.
This issue affects Mediawiki - DataTransfer Extension: from 1.46.0 before 1.47.0.
Which versions are affected by CVE-2026-100242?
How do I fix CVE-2026-100242?
No fix has been published for CVE-2026-100242 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-100242 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100242 exists.
Sources
Also known as GHSA-pc77-95w9-j7gj.