What’s Vulnerable › Vulnerabilities

CVE-2026-55240: Tianji: Remote Code Execution via lodash template evaluate pattern in survey feed templates

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-15 · updated 2026-10-28
• Weakness: CWE-1336

Description

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 disclosure, data modification, or service disruption. This issue is fixed in version 1.31.29.

Affected products

• msgbyte tianji: before 1.31.29

References

• https://github.com/msgbyte/tianji/commit/132ff67907df897d222829ea8ad1a018ff74df48
• https://github.com/msgbyte/tianji/releases/tag/v1.31.29
• https://github.com/msgbyte/tianji/security/advisories/GHSA-5grg-j3cr-3hpm
• https://github.com/msgbyte/tianji/security/advisories/GHSA-5grg-j3cr-3hpm

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