SECURELYN

CVE-2026-55240

Tianji is an open source analytics, uptime monitoring, and server status platform. Prior to 1.31.29, formatString() in src/server/utils/template.ts passes survey feedTemplate and monitor notification templates to lodash template(), while the default evaluate pattern remains enabled. A workspace administrator can store an evaluate block using the % code % form, and the public survey.submit endpoint renders a survey template when an unauthenticated user submits a response. The compiled template executes server-side JavaScript in the Tianji Node.js process, allowing command execution, secret dis…

Scores

9.1
CVSS 9.1 out of 10, critical severity.
0.6%
EPSS 0.6% chance of exploitation in the next 30 days.

The facts

Published
15 October 2026
Last changed
16 October 2026
NVD status
Deferred
Severity
Critical, CVSS 9.1 out of 10 (version 3.1)
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Weakness
Known exploited
Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
EPSS
0.6% chance of exploitation activity in the next 30 days (percentile 46).

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References