CVE-2026-33130 Uptime Kuma: SSTI in Notification Templates Allows Arbitrary File Read (Incomplete Fix for GHSA-vffh-c9pq-4crh)
Attackers can read arbitrary files on the server via Server-side Template Injection in notification templates due to incomplete path validation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-33130?
CVE-2026-33130 is a medium-severity path traversal vulnerability in louislam uptime-kuma, published on 20 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-33130?
It affects 1 product.
Products include Uptime.kuma Uptime Kuma.
How do I fix CVE-2026-33130?
No fix has been published for CVE-2026-33130 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-33130 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33130 exists.