How severe is CVE-2019-18611?

CVE-2019-18611 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2019-18611 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-18611?

CVE-2019-18611 affects Mediawiki Checkuser. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-18611?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2019-18611 published?

CVE-2019-18611 was published on 2019-10-29 and last updated on 2026-06-17.

CVE-2019-18611

CVE-2019-18611 is a medium-severity vulnerability in Mediawiki Checkuser with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Mediawiki Checkuser
Published: 2019-10-29
Last modified: 2026-06-17

Description

An issue was discovered in the CheckUser extension through 1.34 for MediaWiki. Certain sensitive information within oversighted edit summaries made available via the MediaWiki API was potentially visible to users with various levels of access to this extension. Said users should not have been able to view these oversighted edit summaries via the MediaWiki API.

Frequently asked questions

What is CVE-2019-18611?: An issue was discovered in the CheckUser extension through 1.34 for MediaWiki. Certain sensitive information within oversighted edit summaries made available via the MediaWiki API was potentially visible to users with various levels of access to this extension. Said users should not have been able to view these oversighted edit summaries via the MediaWiki API.
How severe is CVE-2019-18611?: CVE-2019-18611 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2019-18611 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-18611?: CVE-2019-18611 affects Mediawiki Checkuser. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-18611?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2019-18611 published?: CVE-2019-18611 was published on 2019-10-29 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mediawiki:checkuser:*:*:*:*:*:mediawiki:*:*

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