What’s Vulnerable › Vulnerabilities

CVE-2026-29779: UptimeFlare: Montior config / Credentials in `workerConfig` exposed in client-side JavaScript bundle

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-07 · updated 2026-06-17
• Weakness: CWE-200

Description

UptimeFlare is a serverless uptime monitoring & status page solution, powered by Cloudflare Workers. Prior to commit 377a596, configuration file uptime.config.ts exports both pageConfig (safe for client use) and workerConfig (server-only, contains sensitive data) from the same module. Due to pages/incidents.tsx importing and using workerConfig directly inside client-side component code, the entire workerConfig object was included in the client-side JavaScript bundle served to all visitors. This issue has been patched via commit 377a596.

Affected products

• lyc8503 UptimeFlare: before 2026-03-04 — fixed in 2026-03-04

How to fix

Upgrade to a fixed version: lyc8503 UptimeFlare 2026-03-04. Check the vendor advisory for mitigations.

References

• https://github.com/lyc8503/UptimeFlare/commit/377a5963c66ba9a798abebfe8d80378b053435e9
• https://github.com/lyc8503/UptimeFlare/issues/198
• https://github.com/lyc8503/UptimeFlare/security/advisories/GHSA-36q9-v7p3-vj6v

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