What’s Vulnerable › Vulnerabilities

CVE-2026-93869: Cotonti through 1.0.0 Open Redirect via Unanchored cot_url_check() Regex

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-18 · updated 2026-09-22
• Weakness: CWE-601

Description

Cotonti through 1.0.0 contains an open redirect vulnerability in the cot_url_check() function that validates redirect destinations using a regular expression lacking an end-of-string anchor. Attackers can bypass the redirect guard by supplying hostnames beginning with the site domain to redirect users to attacker-controlled hosts through the ratings plugin or other redirect callers.

Affected products

• Cotonti: through 1.0.0

References

• https://github.com/Cotonti/Cotonti
• https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/ratings/ratings.ajax.php
• https://github.com/Cotonti/Cotonti/blob/1.0.0/system/functions.php
• https://github.com/Cotonti/Cotonti/issues/1891
• https://github.com/Cotonti/Cotonti/pull/1899
• https://www.vulncheck.com/advisories/cotonti-through-1.0.0-open-redirect-via-unanchored-cot-url-check-regex
• https://github.com/Cotonti/Cotonti/issues/1891

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