CVE-2026-100522

Cotonti through 1.0.0 Reflected XSS via message.php lng parameter

5.1 Medium

Cotonti through 1.0.0 contains a reflected cross-site scripting vulnerability in message.php where the lng parameter is not properly escaped before output in the confirmation dialog. Unauthenticated attackers can craft malicious links with script payloads in the lng parameter to execute arbitrary JavaScript in victim browser sessions.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Active

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: None

Exploit likelihood

0.21%Unchanged since Sep 26, 2026

What each source reports

CVE List Score used 5.1

Cotonti through 1.0.0 Reflected XSS via message.php lng parameter

Record: CVE-2026-100522
CVSS 4.0: 5.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
CVSS 3.1: 6.1 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

EUVDEUVD-2026-87377 5.1

Record: EUVD-2026-87377
CVSS 4.0: 5.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-6r43-xr6w-qprx 5.1

Cotonti through 1.0.0 contains a reflected cross-site scripting vulnerability in message.php...

Record: GHSA-6r43-xr6w-qprx
CVSS 4.0: 5.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/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
CVSS 3.1: 6.1 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

NVD 5.1

Record: CVE-2026-100522
CVSS 4.0: 5.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/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
CVSS 3.1: 6.1 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

OSV 5.1

Cotonti through 1.0.0 Reflected XSS via message.php lng parameter

Record: CVE-2026-100522
CVSS 4.0: 5.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Weakness: CWE-79
Updated: 2026-11-02

Affected products

cotonti

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-2026-100522 is a medium vulnerability (CVSS 5.1) in Cotonti, published September 26, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 11th percentile. No source names a fixed version.