CVE-2026-71285
Uptime Kuma Stored XSS via Matomo Analytics Site ID on Public Status Pages
Description
Uptime Kuma's Matomo analytics integration (server/analytics/matomo-analytics.js) injects the admin-configurable Matomo `siteId` value as a bare, unquoted JavaScript expression inside a <script> block rendered on every public status page: `_paq.push(['setSiteId', ${escapedSiteIdHTMLAttribute}]);`. The escaping pipeline used (jsesc with isScriptContext:true, then html-escaper.escape()) does not escape the characters `]`, `)`, `;`, `(`, which are sufficient to break out of the array/push expression context. A siteId value such as `1]);alert(document.cookie)//`, 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.
INFO
Published Date :
Aug. 5, 2026, 1:24 p.m.
Last Modified :
Aug. 5, 2026, 1:24 p.m.
Remotely Exploit :
Yes !
Source :
309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Affected Products
The following products are affected by CVE-2026-71285
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c |
Solution
- Ensure `siteId` is safely escaped before embedding in JavaScript.
- Validate user input for `siteId` to prevent script injection.
- Update Uptime Kuma to the latest version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-71285.
| URL | Resource |
|---|---|
| https://github.com/louislam/uptime-kuma | |
| https://github.com/louislam/uptime-kuma/blob/master/server/analytics/matomo-analytics.js |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-71285 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-71285
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-71285 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-71285 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Aug. 05, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'louislam', 'product': 'uptime-kuma', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '2.4.0'}], 'programFiles': ['server/analytics/matomo-analytics.js'], 'defaultStatus': 'unaffected'}] Added Description Uptime Kuma's Matomo analytics integration (server/analytics/matomo-analytics.js) injects the admin-configurable Matomo `siteId` value as a bare, unquoted JavaScript expression inside a <script> block rendered on every public status page: `_paq.push(['setSiteId', ${escapedSiteIdHTMLAttribute}]);`. The escaping pipeline used (jsesc with isScriptContext:true, then html-escaper.escape()) does not escape the characters `]`, `)`, `;`, `(`, which are sufficient to break out of the array/push expression context. A siteId value such as `1]);alert(document.cookie)//`, 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. Added CVSS V3.1 AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N Added CWE CWE-79 Added Reference https://github.com/louislam/uptime-kuma Added Reference https://github.com/louislam/uptime-kuma/blob/master/server/analytics/matomo-analytics.js