CVE-2023-37300Public exploitNetwork attack vector

Hidden-username disclosure via missing suppression check

Published Jun 30, 2023 · Updated Nov 27, 2024

Incorrect authorization in MediaWiki CheckUser through 1.39.3 allows remote authenticated users to read hidden usernames through its log API. The CheckUserLog API returns the stored target name without checking whether the account is hidden or whether the caller has the hideuser right. Access requires the checkuser-log right but not suppression rights, exposing hidden account names without granting broader log access.

CVSS severity5.3
Medium
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in MediaWiki CheckUser through 1.39.3 allows remote authenticated users to read hidden usernames through its log API. The CheckUserLog API returns the stored target name without checking whether the account is hidden or whether the caller has the hideuser right. Access requires the checkuser-log right but not suppression rights, exposing hidden account names without granting broader log access.

The record

CVE
CVE-2023-37300
Published
Jun 30, 2023
Updated
Nov 27, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-863, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 30, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 27, 2024Record 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1213Data from Information Repositories

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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