CVE-2026-39937Network attack vector

Email disclosure via incomplete global vanishing

Published Apr 7, 2026 · Updated Apr 7, 2026

Information exposure in the MediaWiki CentralAuth Extension before 1.43 allows remote attackers to access vanished users' email addresses. The global vanishing workflow clears the CentralAuth globaluser email but leaves it in individual wiki user tables because the vanish type is not forwarded to LocalRenameUserJob. Reachability requires a global vanish operation; the bounded consequence is persistence and exposure of the affected account's email in local database records.

CVSS severity8.8
High
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information exposure in the MediaWiki CentralAuth Extension before 1.43 allows remote attackers to access vanished users' email addresses. The global vanishing workflow clears the CentralAuth globaluser email but leaves it in individual wiki user tables because the vanish type is not forwarded to LocalRenameUserJob. Reachability requires a global vanish operation; the bounded consequence is persistence and exposure of the affected account's email in local database records.

The record

CVE
CVE-2026-39937
Published
Apr 7, 2026
Updated
Apr 7, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-212
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 7, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8The Wikimedia FoundationCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:L/SC:L/SI:L/SA:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-212Improper Removal of Sensitive Information Before Storage or Transfer

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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