Is CVE-2026-84465 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-84465 being exploited in the wild.

How severe is CVE-2026-84465?

Informational severity, published 25 September 2026.

Is there a fix for CVE-2026-84465?

A patch was published on 2026-08-03: Fix committed; version 7.1.2 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-84465 attacked?

It is attacked over the network.

Am I affected by CVE-2026-84465?

Check whether you run Zammad at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-84465: Zammad S/MIME signature verification bypass allows sender impersonation

CVE-2026-84465 · Severity: info · Published 2026-09-25

Zammad is a web-based helpdesk and customer support system that handles incoming emails, including digitally signed S/MIME messages. Prior to version 7.1.2, the system fails to properly verify that signing certificates are genuinely trusted; an attacker can forge a certificate bearing a legitimate sender's name and use it to send spoofed emails that Zammad will display as validly signed, potentially deceiving users about the message's authenticity and enabling social engineering attacks.

Technologies: Zammad. Vendors: Zammad.

Quick answers

Is CVE-2026-84465 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-84465 being exploited in the wild.
How severe is CVE-2026-84465?: Informational severity, published 25 September 2026.
Which products and versions are affected?: Zammad 7.1.1 and earlier.
Is there a fix for CVE-2026-84465?: A patch was published on 2026-08-03: Fix committed; version 7.1.2 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-84465 attacked?: It is attacked over the network.
Am I affected by CVE-2026-84465?: Check whether you run Zammad at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability exists in S/MIME signature verification logic that only checks whether a certificate with a matching name exists in the system's certificate store, without validating that the certificate is genuinely trusted or part of a valid trust chain. An attacker with the ability to send email to the system can craft an S/MIME message signed with a self-created certificate bearing a trusted sender's name; Zammad will validate and display the signature as legitimate. This is a cryptographic validation flaw (CWE-295, improper certificate validation) that requires no authentication or user interaction beyond the system receiving an email.

Affected products

Zammad Zammad 7.1.1 and earlier

Timeline

2026-08-04: disclosed
2026-08-03: patched: Fix committed; version 7.1.2 released

References

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