Vulnerability in Louislam Uptime-Kuma
CVE-2026-33130
Uptime Kuma is an open source, self-hosted monitoring tool. In versions 1.23.0 through 2.2.0, the fix from GHSA-vffh-c9pq-4crh doesn't fully work to preventServer-side Template Injection (SSTI). The three mitigations added to the Liquid engine (root, relativeReference, dynamicPartials) only block quoted paths. If a project uses an unquoted absolute path, attackers can still read any file on the server. The original fix in notification-provider.js only constrains the first two steps of LiquidJS's file resolution (via root, relativeReference, and dynamicPartials options), but the third step, the require.resolve() fallback in liquid.node.js has no containment check, allowing unquoted absolute paths like /etc/passwd to resolve successfully. Quoted paths happen to be blocked only because the literal quote characters cause require.resolve('"/etc/passwd"') to throw a MODULE_NOT_FOUND error, not because of any intentional security measure. This issue has been fixed in version 2.2.1.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (37.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 37.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.001
Affected products
- Louislam Uptime-Kuma — versions >= 1.23.0, < 2.2.1
- Uptime.kuma Uptime Kuma
Weakness classification (CWE)
References
- github.com/louislam/uptime-kuma/security/advisories/GHSA-v832-4r73-wx5j (Exploit, Mitigation, Vendor Advisory)
- github.com/advisories/GHSA-vffh-c9pq-4crh (Exploit, Mitigation, Vendor Advisory)
- github.com/louislam/uptime-kuma/releases/tag/2.2.1 (Product, Patch)
Frequently asked questions
- What is CVE-2026-33130?
- CVE-2026-33130 is a medium-severity vulnerability in Louislam Uptime-Kuma, classified under PHP Remote File Inclusion. CVSS score: 6.5/10. Published 2026-03-20.
- How severe is CVE-2026-33130?
- Medium severity. CVSS v3 base score is 6.5 out of 10.