CVE-2026-71285

8.1 HIGHpublic exploit available

Published 2026-08-05 · Updated 2026-08-10

AI risk analysis

Summary: The flaw allows unauthenticated visitors to execute arbitrary JavaScript due to improper handling of user input in Matomo analytics integration, leading to potential session theft and full page takeover.
Exploitability: Exploitation is relatively easy once an attacker can control the siteId value, requiring only basic scripting knowledge.
Blast radius: If exploited, this flaw could lead to significant damage, including unauthorized access to user sessions and complete control over the affected website.
Prioritized remediation: Update Uptime Kuma to a version that addresses this vulnerability or remove Matomo analytics integration until a fix is available.

rcewebjs-injectionsession-theft

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD description

Uptime Kuma's Matomo analytics integration (server/analytics/matomo-analytics.js) injects the admin-configurable Matomo value as a bare, unquoted JavaScript expression inside a <script> block rendered on every public status page. A siteId value such as , once saved by an editor/admin, executes arbitrary JavaScript for every unauthenticated visitor of the public /status/<slug> page, enabling session-cookie theft and full page takeover.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N

Weaknesses

CWE-79

Public exploit & PoC references

All references

Source data: NVD (nvd.nist.gov), public domain. Exploit-DB.ai adds local AI analysis for defensive use only.