Cyber Resilience

CVE-2026-39937

High

Published: 07 April 2026

Published
07 April 2026
Modified
08 April 2026
KEV Added
Patch
CVSS Score v4 8.8 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:L/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0026 17.4th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-39937 is a high-severity Improper Removal of Sensitive Information Before Storage or Transfer (CWE-212) vulnerability. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 17.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Improper removal of sensitive information before storage or transfer vulnerability in The Wikimedia Foundation Mediawiki - CentralAuth Extension allows Resource Leak Exposure. The issue has been remediated on the `master` branch, and in the release branches for MediaWiki versions 1.43,…

more

1.44, and 1.45.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
Why these techniques?

Vuln in public-facing MediaWiki extension enables exploitation for sensitive data/credential exposure via improper sanitization on storage/transfer.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

Affected Assets

MediaWiki
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-212

Eradication of spilled information from contaminated systems mitigates the effects of improper removal of sensitive data before storage or transfer.

addresses: CWE-212

The control requires verified removal of sensitive data before media is made available at a reduced classification level, directly addressing improper removal prior to storage or transfer.

addresses: CWE-212

Explicit procedures to delete inaccurate or outdated PII directly mitigate improper removal of sensitive information before storage or transfer.

addresses: CWE-212

Retention policies enforce removal or sanitization of sensitive data before storage or transfer per regulatory requirements.

addresses: CWE-212

The explicit requirement to delete inaccurate/outdated PII implements proper removal of sensitive information before further storage or transfer.

addresses: CWE-212

The control implements proper removal of sensitive information before storage or transfer of datasets.

addresses: CWE-212

The generate-on-demand-and-delete requirement enforces removal of sensitive information before storage or transfer, preventing improper retention.

addresses: CWE-212

Requires explicit removal of sensitive information prior to component transfer or disposal, reducing exposure from retained data.

References