CVE-2026-3107

Critical

Published: 31 March 2026

Published

31 March 2026

Modified

07 April 2026

KEV Added

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Patch

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CVSS Score v4 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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

EPSS Score 0.0013 3.2th percentile

Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-3107 is a critical-severity Cross-site Scripting (CWE-79) vulnerability in Teampass Teampass. Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 3.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-17347
🇪🇸 INCIBE: www.incibe.es

Vulnerability details

Stored Cross-Site Scripting (XSS) in Teampass versions prior to 3.1.5.16, affecting the password manager's password import functionality at the endpoint 'redacted/index.php?page=items'. The application fails to properly sanitize and encode user-input data during the import process, allowing malicious JavaScript payloads to…

be persistently stored in the database. When other users view the imported passwords, the payload is automatically executed in their browsers, resulting in a stored XSS condition at the endpoint 'redacted/index.php?page=items'. Exploiting this vulnerability allows an attacker to execute arbitrary JavaScript code in the context of multiple users and the administrator, which can lead to session hijacking, credential theft, privilege abuse, and compromise of application integrity.

CWE(s): CWE-79

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1059.007 JavaScript Execution

Adversaries may abuse various implementations of JavaScript for execution.

attack.mitre.org →

T1185 Browser Session Hijacking Collection

Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.

attack.mitre.org →

T1539 Steal Web Session Cookie Credential Access

An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.

attack.mitre.org →

Why these techniques?

Stored XSS directly enables web app exploitation (T1190) and arbitrary JS execution (T1059.007) leading to session hijacking (T1185) and cookie theft (T1539).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0