CVE-2026-29779
Published: 07 March 2026
Summary
CVE-2026-29779 is a high-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability in Lyc8503 Uptimeflare. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Credentials In Files (T1552.001); ranked at the 12.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Automated marking applies security attributes to system outputs, making it harder for attackers to exploit unmarked sensitive information leading to unauthorized exposure.
Proper attribute retention and permitted-value enforcement limits unauthorized actors from accessing sensitive information lacking correct labels.
Prevents unauthorized exposure of sensitive information by prohibiting untrusted external systems from processing or storing it.
By enforcing authorization matching prior to sharing, the control reduces the risk of exposing sensitive information to unauthorized actors.
Review and removal of nonpublic information from publicly accessible systems directly prevents exposure of sensitive data to unauthorized actors.
Data mining protection mechanisms detect and block unauthorized bulk extraction of sensitive data, directly mitigating exposure to unauthorized actors.
Literacy training teaches users to recognize and avoid actions that result in unauthorized exposure of sensitive information.
Retaining and monitoring training records confirms personnel have completed privacy and security awareness training on handling sensitive data, reducing the chance of unauthorized exposure due to lack of knowledge.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Vulnerability directly exposes workerConfig secrets (incl. credentials/tokens) inside publicly served client-side JS bundles, enabling collection of unsecured credentials from files without server compromise.
NVD 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…
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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.
Deeper analysisAI
CVE-2026-29779 affects UptimeFlare, a serverless uptime monitoring and status page solution powered by Cloudflare Workers. Prior to commit 377a596, the configuration file uptime.config.ts exported both pageConfig, which is safe for client-side use, and workerConfig, which contains sensitive server-only data, from the same module. The pages/incidents.tsx file imported and used workerConfig directly within client-side component code, resulting in the entire workerConfig object being bundled into the client-side JavaScript served to all visitors. This vulnerability, classified under CWE-200 (Exposure of Sensitive Information), carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).
Any unauthenticated visitor to an affected UptimeFlare deployment can exploit this vulnerability with low complexity over the network and without user interaction. By simply loading the incidents page or related client-side resources, attackers gain access to the sensitive data within the workerConfig object embedded in the JavaScript bundle, enabling high-impact confidentiality breaches such as exposure of configuration secrets.
The issue has been patched in commit 377a596, as detailed in the GitHub security advisory GHSA-36q9-v7p3-vj6v, issue #198, and the commit itself. Security practitioners should ensure deployments are updated to this commit or later to mitigate exposure of workerConfig data.
Details
- CWE(s)