5.1
MEDIUM CVSS 4.0
CVE-2026-63205
Zammad: Channel admins can read unauthorized attachments via signature rich-text body
Description

Zammad is a web based open source helpdesk/customer support system. Prior to 7.1.2, when creating or updating an email signature, Zammad processes inline images referenced in the signature body. If a signature body contains an HTML img tag pointing to any existing attachment, the system copies that attachment into a new signature-owned record, without checking whether the user has permission to access the original attachment. The newly created copy is then downloadable by the same channel-admin user, because attachment access is determined by the copy's owner (the signature), not the original object (e.g., a ticket or knowledge-base article). This allows a user with any of the admin.channel_email, admin.channel_google, admin.channel_microsoft365, or admin.channel_microsoft_graph permissions to read attachments they would otherwise be denied access to, such as ticket attachments belonging to groups they are not a member of. 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-2026-63205 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 4.0 MEDIUM [email protected]
Solution
Update Zammad to version 7.1.2 or later to fix improper attachment access control.
  • Update Zammad to version 7.1.2 or later.
  • Verify attachment access controls after update.
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-2026-63205.

URL Resource
https://github.com/zammad/zammad/commit/f3e4da83621efad8443a4e9fe6bd87befad47c44
https://github.com/zammad/zammad/security/advisories/GHSA-pp8r-x7pp-5qj5
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-63205 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-2026-63205 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-2026-63205 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-63205 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. Prior to 7.1.2, when creating or updating an email signature, Zammad processes inline images referenced in the signature body. If a signature body contains an HTML img tag pointing to any existing attachment, the system copies that attachment into a new signature-owned record, without checking whether the user has permission to access the original attachment. The newly created copy is then downloadable by the same channel-admin user, because attachment access is determined by the copy's owner (the signature), not the original object (e.g., a ticket or knowledge-base article). This allows a user with any of the admin.channel_email, admin.channel_google, admin.channel_microsoft365, or admin.channel_microsoft_graph permissions to read attachments they would otherwise be denied access to, such as ticket attachments belonging to groups they are not a member of. This issue is fixed in version 7.1.2.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/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-639
    Added CWE CWE-862
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/63xxx/CVE-2026-63205.json">CVE-2026-63205</a>
    Added Reference https://github.com/zammad/zammad/commit/f3e4da83621efad8443a4e9fe6bd87befad47c44
    Added Reference https://github.com/zammad/zammad/security/advisories/GHSA-pp8r-x7pp-5qj5
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.