5.3
MEDIUM CVSS 4.0
CVE-2026-61855
Zammad: Invalid PGP Detached Signatures Reported as Good Signature on Inbound Mail
Description

Zammad is a web based open source helpdesk/customer support system. In 7.0.3 and 7.1.1, under certain conditions, Zammad's verification of inbound PGP-signed email can mark a message as carrying a valid ("Good") PGP signature from a registered sender key, even though the displayed message content is not actually covered by that signature. As a result, the inbound article may be stored with a successful signature status that does not reflect the authenticity of the shown content. This can mislead agents who rely on the signature indicator when assessing the trustworthiness of incoming mail. This issue is fixed in version 7.1.2.

INFO

Published Date :

Sept. 25, 2026, 7:17 p.m.

Last Modified :

Sept. 25, 2026, 7:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-61855 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 4.0 MEDIUM [email protected]
Solution
Update Zammad to version 7.1.2 to fix PGP signature verification issues.
  • Update Zammad to version 7.1.2.
  • Verify PGP signature verification logic.
  • Train users on signature verification limitations.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-61855.

URL Resource
https://github.com/zammad/zammad/commit/dd22716ced9f18861ed6f3b326c9d332c8c2072d
https://github.com/zammad/zammad/security/advisories/GHSA-r957-vp26-563q
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-61855 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-61855 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-61855 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-61855 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 25, 2026

    Action Type Old Value New Value
    Added Description Zammad is a web based open source helpdesk/customer support system. In 7.0.3 and 7.1.1, under certain conditions, Zammad's verification of inbound PGP-signed email can mark a message as carrying a valid ("Good") PGP signature from a registered sender key, even though the displayed message content is not actually covered by that signature. As a result, the inbound article may be stored with a successful signature status that does not reflect the authenticity of the shown content. This can mislead agents who rely on the signature indicator when assessing the trustworthiness of incoming mail. This issue is fixed in version 7.1.2.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-347
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/61xxx/CVE-2026-61855.json">CVE-2026-61855</a>
    Added Reference https://github.com/zammad/zammad/commit/dd22716ced9f18861ed6f3b326c9d332c8c2072d
    Added Reference https://github.com/zammad/zammad/security/advisories/GHSA-r957-vp26-563q
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 25, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-61855', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-25T19:02:32.825707Z'}
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.