PT-2026-98949 · Zammad · Zammad
CVE-2026-56735
·
Published
2026-09-25
·
Updated
2026-09-25
CVSS v4.0
5.3
Medium
| Vector | AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/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 |
Name of the Vulnerable Software and Affected Versions
Zammad versions prior to 7.0.2
Zammad versions prior to 7.1.0
Description
The HTML sanitizer
HtmlSanitizer::Strict fails to block external URLs within the srcset attribute of <img> tags. While other external URLs are blocked to prevent remote content loading, this oversight allows an attacker to embed arbitrary external URLs by sending an email. When an agent views the affected ticket, the browser silently loads the attacker-controlled URL, leading to the leakage of the agent's IP address, User-Agent, Referer, and the timestamp of when the ticket was viewed. This bypass enables the use of tracking pixels and external content loading, compromising user privacy.Recommendations
Update to version 7.0.2.
Update to version 7.1.0.
Exploit
Fix
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Weakness Enumeration
Related Identifiers
Affected Products
Zammad