CVE-2026-63205: Auth Bypass

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.

Is your site exposed to CVE-2026-63205?

Run a free security scan — no signup, results in seconds.

Weakness Type (CWE)

CWE-639 CWE-639

CWE-862 Missing Authorization

References

Other References

https://github.com/zammad/zammad/commit/f3e4da83621efad8443a4e9fe6bd87befad47c44 https://github.com/zammad/zammad/security/advisories/GHSA-pp8r-x7pp-5qj5

Frequently Asked Questions

What is CVE-2026-63205? +

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.

How do I check if I'm vulnerable to CVE-2026-63205? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-40570

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, the `load_customer_info` action in `POST /conversation/ajax` …

CVE-2026-9152

A missing authentication vulnerability exists in the Altium 365 SearchService. A legacy SOAP endpoint exposes search index operations without requiring …

CVE-2026-40866

Horilla is a free and open source Human Resource Management System (HRMS). In 1.5.0, an insecure direct object reference in …

CVE-2026-40865

Horilla is a free and open source Human Resource Management System (HRMS). In 1.5.0, an insecure direct object reference in …

CVE-2026-6375

A vulnerability in SpiceJet’s booking API allows unauthenticated users to query passenger name records (PNRs) without any access controls. Because …

CVE-2025-15626

Authenticated user can bypass authorization in Ribblr - Crochet & Knitting iOS application

CVE-2026-63205