CVE-2026-113583
Published:October 20, 2026
Updated:October 20, 2026
Cypht webmail 2.0.0 through 2.12.2 contains a DOM-based cross-site scripting vulnerability that allows remote attackers to execute arbitrary JavaScript by crafting malicious alt text or URL values in an HTML email's external image tag when ALLOW_EXTERNAL_IMAGE_SOURCES is enabled. Attackers can send a specially crafted email so that when the victim opens it, the externalResources.js code builds the blocked-image notice using innerHTML with decoded email-derived values, triggering script execution in the victim's authenticated session to read mailboxes, send email, or change settings.
Affected Packages
https://github.com/cypht-org/cypht.git (GITHUB):
Affected version(s) >=v2.0.0 <v2.13.0Fix Suggestion:
Update to version v2.13.0jason-munro/cypht (PHP):
Affected version(s) >=v2.0.1 <v2.13.0Fix Suggestion:
Update to version v2.13.0Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')