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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction Active

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact Low

Subsequent System Integrity Impact Low

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact Low

Integrity Impact Low

Availability Impact None

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00188.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Cotonti Cotonti unaffected
Version Status Constraints
0 affected ≤ 1.0.0

No data.

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors Products
Cotonti Subscribe
Siena Subscribe

Project Subscriptions

Vendors Products
Cotonti Subscribe
Cotonti Siena Subscribe
Siena Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/Cotonti/Cotonti cve-icon cve-icon
https://github.com/Cotonti/Cotonti/blob/1.0.0/message.php cve-icon cve-icon
https://github.com/Cotonti/Cotonti/blob/1.0.0/system/common.php cve-icon cve-icon
https://github.com/Cotonti/Cotonti/issues/1907 cve-icon cve-icon
https://github.com/Cotonti/Cotonti/pull/1908 cve-icon cve-icon
https://www.vulncheck.com/advisories/cotonti-through-1.0.0-open-redirect-via-message-php-redirect-parameter cve-icon cve-icon
History

Mon, 05 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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

Sat, 26 Sep 2026 09:15:00 +0000

Type Values Removed Values Added
First Time appeared Cotonti siena
Vendors & Products Cotonti siena

Sat, 26 Sep 2026 01:15:00 +0000

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'}

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-05T14:55:04.892Z

Reserved: 2026-09-26T00:48:22.887Z

Link: CVE-2026-100523

cve-icon Vulnrichment

Updated: 2026-10-05T14:51:03.485Z

cve-icon NVD

Status : Deferred

Published: 2026-09-26T01:17:00.870

Modified: 2026-10-05T15:17:10.117

Link: CVE-2026-100523

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-26T09:00:13Z

Weaknesses