CVE-2026-77506

Znuny before LTS 6.5.22 allows AgentTicketEmailResend template XSS.

4.8 MediumFix available

Znuny before LTS 6.5.22 allows AgentTicketEmailResend template XSS.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: High
User interaction: Required

What an attacker can affect

Confidentiality: Low
Integrity: Low
Availability: None

Exploit likelihood

0.24%Unchanged since Aug 21, 2026

What each source reports

CVE List Score used 4.8

Znuny before LTS 6.5.22 allows AgentTicketEmailResend template XSS.

Record: CVE-2026-77506
CVSS 3.1: 4.8 MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

EUVDEUVD-2026-63586 4.8

Znuny before LTS 6.5.22 allows AgentTicketEmailResend template XSS.

Record: EUVD-2026-63586
CVSS 3.1: 4.8 MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-4mvf-wmjf-gpfv 4.8

Znuny before LTS 6.5.22 allows AgentTicketEmailResend template XSS.

Znuny before LTS 6.5.22 allows AgentTicketEmailResend template XSS.

Record: GHSA-4mvf-wmjf-gpfv
CVSS 3.1: 4.8 MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

NVD 4.8

Znuny before LTS 6.5.22 allows AgentTicketEmailResend template XSS.

Record: CVE-2026-77506
CVSS 3.1: 4.8 MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

OSVDEBIAN-CVE-2026-77506 4.8

Znuny before LTS 6.5.22 allows AgentTicketEmailResend template XSS.

Record: DEBIAN-CVE-2026-77506
CVSS 3.1: 4.8 MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-77506 4.8

Znuny before LTS 6.5.22 allows AgentTicketEmailResend template XSS.

Record: UBUNTU-CVE-2026-77506
CVSS 3.1: 4.8 MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Updated: 2026-11-02

Affected products

znuny

Affected packages

Affected packages
Package	Affected	Fixed
`znuny` Debian:12	All versions, plus listed versions 6.3.2-36.3.3-16.3.3-1~bpo11+16.3.4-16.3.4-1~bpo11+1 Show 45 moreShow less 6.4.2-16.4.2-1~bpo11+16.4.2-26.4.3-16.4.3-1~bpo11+16.4.4-16.4.5-16.4.5-1~bpo11+16.4.5-26.5.1-16.5.10-16.5.10-1~bpo12+16.5.11-16.5.11-1~bpo12+16.5.13-16.5.14-16.5.14-1~bpo12+16.5.15-16.5.15-26.5.15-2~bpo12+16.5.16-16.5.18-16.5.18-1~bpo13+16.5.19-16.5.20-16.5.21-16.5.22-16.5.22-1~bpo13+16.5.23-16.5.23-1~bpo13+16.5.24-16.5.24-1~bpo13+16.5.25-16.5.25-1~bpo13+16.5.26-16.5.26-1~bpo13+16.5.3-16.5.3-1~bpo12+16.5.4-16.5.4-1~bpo12+16.5.5-16.5.5-1~bpo12+16.5.6-16.5.6-1~bpo12+16.5.8-1	None known
`znuny` Debian:13	All versions, plus listed versions 6.3.2-36.3.3-16.3.3-1~bpo11+16.3.4-16.3.4-1~bpo11+1 Show 45 moreShow less 6.4.2-16.4.2-1~bpo11+16.4.2-26.4.3-16.4.3-1~bpo11+16.4.4-16.4.5-16.4.5-1~bpo11+16.4.5-26.5.1-16.5.10-16.5.10-1~bpo12+16.5.11-16.5.11-1~bpo12+16.5.13-16.5.14-16.5.14-1~bpo12+16.5.15-16.5.15-26.5.15-2~bpo12+16.5.16-16.5.18-16.5.18-1~bpo13+16.5.19-16.5.20-16.5.21-16.5.22-16.5.22-1~bpo13+16.5.23-16.5.23-1~bpo13+16.5.24-16.5.24-1~bpo13+16.5.25-16.5.25-1~bpo13+16.5.26-16.5.26-1~bpo13+16.5.3-16.5.3-1~bpo12+16.5.4-16.5.4-1~bpo12+16.5.5-16.5.5-1~bpo12+16.5.6-16.5.6-1~bpo12+16.5.8-1	None known
`znuny` Debian:14	before 6.5.22-1, plus listed versions 6.3.2-36.3.3-16.3.3-1~bpo11+16.3.4-16.3.4-1~bpo11+1 Show 39 moreShow less 6.4.2-16.4.2-1~bpo11+16.4.2-26.4.3-16.4.3-1~bpo11+16.4.4-16.4.5-16.4.5-1~bpo11+16.4.5-26.5.1-16.5.10-16.5.10-1~bpo12+16.5.11-16.5.11-1~bpo12+16.5.13-16.5.14-16.5.14-1~bpo12+16.5.15-16.5.15-26.5.15-2~bpo12+16.5.16-16.5.18-16.5.18-1~bpo13+16.5.19-16.5.20-16.5.21-16.5.22-1~bpo13+16.5.3-16.5.3-1~bpo12+16.5.4-16.5.4-1~bpo12+16.5.5-16.5.5-1~bpo12+16.5.6-16.5.6-1~bpo12+16.5.8-16.5.8-1~bpo12+16.5.9-16.5.9-1~bpo12+1	6.5.22-1
`otrs2` Ubuntu:16.04:LTS	All versions, plus listed versions 4.0.10-15.0.1-15.0.1-25.0.2-15.0.3-15.0.5-15.0.6-15.0.7-1	None known
`otrs2` Ubuntu:18.04:LTS	All versions, plus listed versions 5.0.23-15.0.24-16.0.1-16.0.2-16.0.3-16.0.4-16.0.5-1	None known
`otrs2` Ubuntu:20.04:LTS	All versions, plus listed versions 6.0.20-16.0.23-26.0.24-16.0.25-16.0.25-26.0.25-36.0.26-1	None known
`otrs2` Ubuntu:22.04:LTS	All versions, plus listed versions 6.0.32-66.1.2-16.2.1-16.2.2-2	None known
`znuny` Ubuntu:24.04:LTS	All versions, plus listed versions 6.5.3-16.5.4-16.5.5-16.5.6-1	None known
`znuny` Ubuntu:26.10	All versions, plus listed versions 6.5.18-16.5.20-16.5.21-16.5.22-16.5.23-1	None known
`znuny` Ubuntu:26.04:LTS	All versions, plus listed versions 6.5.15-26.5.18-1	None known

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-77506 is a medium vulnerability (CVSS 4.8) in Znuny, published August 20, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.24%, the 15th percentile. Fixed in znuny 6.5.22-1.

References

This page doesn't list everything

Left out here: 6 versions. The JSON record has them.