CVE-2026-100523

Cotonti through 1.0.0 Open Redirect via message.php redirect parameter

Published Sep 26, 2026 CVSS 4.0 · 5.1 Medium EPSS < 1% KEV · Not listed
Description
Cotonti through 1.0.0 contains an open redirect vulnerability in message.php that base64-decodes the redirect parameter without domain validation. Unauthenticated attackers can craft malicious links with encoded external URLs to redirect users to arbitrary sites via meta refresh tags for phishing attacks.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Cotonti siena
Vendors & Products Cotonti siena
Type Values Removed Values Added
Description Cotonti through 1.0.0 contains an open redirect vulnerability in message.php that base64-decodes the redirect parameter without domain validation. Unauthenticated attackers can craft malicious links with encoded external URLs to redirect users to arbitrary sites via meta refresh tags for phishing attacks.
Title Cotonti through 1.0.0 Open Redirect via message.php redirect parameter
First Time appeared Cotonti
Cotonti cotonti Siena
Weaknesses CWE-601
CPEs cpe:2.3:a:cotonti:cotonti_siena:*:*:*:*:*:*:*:*
Vendors & Products Cotonti
Cotonti cotonti Siena
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 5, 2026, 2:55 PM
Reserved
Sep 26, 2026, 12:48 AM
Status
Deferred
Published
Sep 26, 2026, 1:17 AM
Modified
Oct 5, 2026, 3:17 PM