CVE-2026-33130

Uptime Kuma: SSTI in Notification Templates Allows Arbitrary File Read (Incomplete Fix for GHSA-vffh-c9pq-4crh)

MEDIUM
6.5
CVSS Score
Published: March 20, 2026 at 09:50 AM UTC
Updated: June 17, 2026 at 10:36 AM UTC
2 products affected across 2 vendorsUptime.kumaKuma Uptime Kuma

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.3%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

1.23.0 ≤ v < 2.2.1
v < 2.2.1
Affected range stops below 2.2.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_CONFIRMExploitMitigationVendor Advisory
Source: cverecord
https://github.com/louislam/uptime-kuma/security/advisories/GHSA-v832-4r73-wx5j
x_refsource_MISCExploitMitigationVendor Advisory
Source: cverecord
https://github.com/advisories/GHSA-vffh-c9pq-4crh
x_refsource_MISCPatchProduct
Source: cverecord
https://github.com/louislam/uptime-kuma/releases/tag/2.2.1

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-98CWE-1336

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