Quick answers
- Is CVE-2026-77506 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-77506 being exploited in the wild.
- How severe is CVE-2026-77506?
- Medium severity, with a CVSS score of 4.8, published 20 August 2026.
- Which products and versions are affected?
- Znuny 6.0, 6.1, 6.2, 6.3, 6.4; Znuny LTS 6.5.1 to 6.5.21.
- Is there a fix for CVE-2026-77506?
- A patch was published on 2026-08-20: Fixed in Znuny LTS 6.5.22 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-77506 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-77506?
- Check whether you run Znuny or Znuny LTS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A stored cross-site scripting (XSS) vulnerability exists in the AgentTicketEmailResend template within Znuny's agent interface. The vulnerability arises from user-controlled data being rendered without proper HTML output encoding, allowing an authenticated agent to inject arbitrary HTML or JavaScript code. The attack requires an agent with access to the agent interface (authenticated attack) and relies on social engineering or user interaction to trick another agent into viewing a malicious email resend payload. An attacker can execute arbitrary JavaScript in the victim agent's browser session within the Znuny domain, potentially compromising the victim's account or stealing session tokens. Znuny LTS 6.5.22 and later versions contain the fix.
Affected products
- Znuny Znuny LTS 6.5.1 to 6.5.21
- Znuny Znuny 6.0, 6.1, 6.2, 6.3, 6.4
Timeline
- 2026-06-24: disclosed
- 2026-08-20: patched: Fixed in Znuny LTS 6.5.22