Cross-Site Scripting (XSS) in Uptime Kuma (CVE-2026-71285)
Summary
Cross-site scripting in Uptime Kuma (CVE-2026-71285). Confidential information can be exposed externally. Exploitable via siteId.
Original description
The description as published by the source.
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 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/ page, enabling session-cookie theft and full page takeover.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-71285 has been found in Uptime Kuma.
Attackers can target a specific entry point like siteId over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Uptime Kuma CVE-2026-71285" on the vendor's site.
CVE-2026-71285 (Uptime Kuma) — CWE-79 / CVSS v3 8.1
Attack vector: remote (network-reachable)
Attack surface: siteId
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in Uptime Kuma. Attackers reach the vulnerable code path via siteId.
Check the vendor advisory for the affected versions of Uptime Kuma. Attack surface: siteId.
Severity: High (CVSS 8.1/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Uptime Kuma を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- web github.com