9.1

CVE-2026-100240: wikimedia foundation mediawiki - templatesandbox extension Missing Authorization

CVSS: 9.1v3.1CriticalAwaiting analysis
Published 29-09-2026Last modified 01-10-2026
Open JSON

Vulnerability summary

CVE-2026-100240 is a critical (CVSS 9.1) Missing Authorization vulnerability in wikimedia foundation mediawiki - templatesandbox extension. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 21.2% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.1/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.30%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 29-09-2026
    PublishedVulnerability first disclosed.
  2. 01-10-2026
    Last modifiedVulnerability information updated.

Description

Missing Authorization vulnerability in Wikimedia Foundation Mediawiki - TemplateSandbox Extension allows Accessing Functionality Not Properly Constrained by ACLs. This issue affects Mediawiki - TemplateSandbox Extension: from * before 1.46.1, 1.45.5, 1.43.10.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.30%

Chance of exploitation in the next 30 days

Percentile

21%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

30-09-202621-10-2026
EPSS score
0.30%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Wikimedia foundation1 product

1 vendor · 1 product

References

2 links