Attack Chain

1. An unauthenticated attacker sends an HTTP GET request to either the /api/system/fileView or /api/system/fileDownload endpoint.
2. The attacker includes a file parameter in the request's query string.
3. The value of the file parameter contains a path traversal sequence (e.g., ../../../../etc/passwd) or an absolute path (e.g., /etc/shadow, C:\\Windows\\System32\\drivers\\etc\\hosts).
4. The vulnerable Meshery application processes the request, passing the malicious file parameter directly to the os.Open function without proper sanitization or validation.
5. The os.Open function attempts to read the file specified by the attacker's manipulated path outside the intended directory.
6. The content of the requested arbitrary file is returned in the HTTP response body to the attacker.
7. The attacker successfully exfiltrates sensitive system files, configuration, or credentials.

Impact

Successful exploitation of CVE-2026-65919 allows an unauthenticated attacker to read any file on the server hosting Meshery. This could lead to the exposure of highly sensitive information, such as system configuration files, private keys, database credentials, user account details, and other proprietary data. While the NVD does not specify observed exploitation in the wild or victim counts, the ability for any unauthenticated actor to access arbitrary files without interaction makes this a critical data confidentiality risk. Compromised data could lead to further system compromise, privilege escalation, or lateral movement within an organization's network.

Recommendation

• Patch CVE-2026-65919 immediately by updating Meshery to version 1.0.57 or later, as referenced in https://github.com/meshery/meshery/releases/tag/v1.0.57.
• Deploy the Sigma rule "Detects CVE-2026-65919 Exploitation - Meshery Path Traversal" to your SIEM to detect attempts to exploit the /api/system/fileView and /api/system/fileDownload endpoints with path traversal sequences.
• Ensure webserver logs (category: webserver) are collected and monitored for suspicious activity, particularly for requests containing unusual characters or pathing in URI query parameters.