All vulnerabilities
CVE-2026-56734GHSA-q3cr-3wq3-29hx

Zammad: Avatar Image URL Server-Side Request Forwarding

zammad zammadApplications & CMS
Open in ThreatlineRecord JSON
CVSS
5.3Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.40%Chance of exploitation activity in the next 30 days, higher than 32% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published25 Sep 2026Updated 29 Sep 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Description

Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2, during federated authentication (OAuth/OIDC/SAML), a profile image URL from the external identity provider is fetched without verifying the target address. An actor who controls their profile at a connected provider may cause the server to connect to internal network locations. Response timing and error patterns differ between reachable and unreachable targets, allowing internal service probing. Worker processes may be blocked for several seconds per request. Requires a configured external authentication provider where the actor can modify their profile image URL. This issue is fixed in version 7.0.2.

Text from CVE List

Affected versions 2

  • zammadaffected: < 7.0.2CVE List
  • Zammad<= 7.0.1GitHub

References 3