CVE-2026-84465
HIGH
7,1
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: passive
Confidentiality: N/A
Integrity: N/A
Availability: N/A
Description
AI Translation Available
Zammad is a web based open source helpdesk/customer support system. Prior to 7.1.2, when Zammad checks the digital signature on an incoming S/MIME-signed email, it does not verify that the signing certificate is genuinely trusted, it only checks whether a certificate with a matching name is already stored in the system. An attacker can create their own certificate using the name of a real, previously trusted sender and use it to send a forged email. Zammad will display that email with the same 'validly signed' indicator as a genuine message from the real sender, even though the attacker never had access to that sender's actual certificate or private key. This issue is fixed in version 7.1.2.
290
Authentication Bypass by Spoofing
IncompleteCommon Consequences
Security Scopes Affected:
Access Control
Potential Impacts:
Bypass Protection Mechanism
Gain Privileges Or Assume Identity
Applicable Platforms
All platforms may be affected
295
Improper Certificate Validation
DraftCommon Consequences
Security Scopes Affected:
Integrity
Authentication
Potential Impacts:
Bypass Protection Mechanism
Gain Privileges Or Assume Identity
Applicable Platforms
Technologies:
Not Technology-Specific, Web Based, Mobile
347
Improper Verification of Cryptographic Signature
DraftCommon Consequences
Security Scopes Affected:
Access Control
Integrity
Confidentiality
Potential Impacts:
Gain Privileges Or Assume Identity
Modify Application Data
Execute Unauthorized Code Or Commands
Applicable Platforms
All platforms may be affected
https://github.com/zammad/zammad/commit/9a07d0b8214ac4e8e10c23fce71d613bd0625524
https://github.com/zammad/zammad/security/advisories/GHSA-m9ff-hjr3-93h4