What is CVE-2026-93871?

CVE-2026-93871 is a medium-severity vulnerability in Cotonti, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 5.4/10. Published 2026-09-18.

How severe is CVE-2026-93871?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Open Redirect in Cotonti

CVE-2026-93871

Cotonti through 1.0.0 fails to validate redirect destinations in page bodies prefixed with redir:, allowing authenticated users with page creation or edit permissions to store redirects to arbitrary external hosts. Attackers can craft pages on trusted domains that redirect visitors to malicious sites for phishing attacks without administrative privileges.

Vulnerability class: Open Redirect

Published 2026-09-18 · last modified 2026-09-22.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (19.8th percentile), scored 2026-11-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 19.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Cotonti

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

References

github.com/Cotonti/Cotonti/issues/1893 (issue-tracking)
github.com/Cotonti/Cotonti/pull/1901 (issue-tracking, patch)
github.com/Cotonti/Cotonti/blob/1.0.0/modules/page/inc/page.main.php (technical-description)
github.com/Cotonti/Cotonti (product)
www.vulncheck.com/advisories/cotonti-through-1.0.0-stored-open-redirect-via-pag… (third-party-advisory)

Frequently asked questions

What is CVE-2026-93871?: CVE-2026-93871 is a medium-severity vulnerability in Cotonti, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 5.4/10. Published 2026-09-18.
How severe is CVE-2026-93871?: Medium severity. CVSS v3 base score is 5.4 out of 10.