CVE-2011-1766

CVE-2011-1766 is a medium-severity vulnerability in Mediawiki with a CVSS 2.0 base score of 5.8. 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-287.

Key facts

Description

includes/User.php in MediaWiki before 1.16.5, when wgBlockDisablesLogin is enabled, does not clear certain cached data after verification of an auth token fails, which allows remote attackers to bypass authentication by creating crafted wikiUserID and wikiUserName cookies, or by leveraging an unattended workstation.

Frequently asked questions

What is CVE-2011-1766?
includes/User.php in MediaWiki before 1.16.5, when wgBlockDisablesLogin is enabled, does not clear certain cached data after verification of an auth token fails, which allows remote attackers to bypass authentication by creating crafted wikiUserID and wikiUserName cookies, or by leveraging an unattended workstation.
How severe is CVE-2011-1766?
CVE-2011-1766 has a CVSS 2.0 base score of 5.8, rated medium severity.
Is CVE-2011-1766 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2011-1766?
CVE-2011-1766 primarily affects Mediawiki. In total, 137 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2011-1766?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2011-1766 published?
CVE-2011-1766 was published on 2011-05-23 and last updated on 2026-06-16.

References

Affected products (137)

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