CVE-2026-77357: high-severity vulnerability in mesop-dev mesop
Mesop: DoS in /hot-reload endpoint allows unauthenticated attacker to exhaust worker threads and crash the server
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.7epss 0.5%
Mesop is a Python-based UI framework that allows users to build web applications. Prior to 1.3.3, applications running in debug mode expose a GET /hot-reload endpoint whose unbounded loop depends on the user-supplied counter parameter, allowing an unauthenticated attacker to hold worker threads with high counter values until the worker pool is exhausted and the server becomes unavailable. A single unauthenticated attacker can crash the Mesop server with minimal effort. Because the attack leverages worker exhaustion, the server remains unresponsive until it is manually restarted. This issue is fixed in version 1.3.3.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected products
mesop-dev · mesopRelated CVEs — mesop-dev mesop
In the same product, most dangerous first.
CVE-2026-33057CRITICALMesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-pyEPSS 5.4%CVE-2026-34824HIGHMesop: Unbounded Thread Creation in WebSocket Handler Leads to Denial of ServiceEPSS 0.8%CVE-2026-33054CRITICALMesop: Path Traversal utilizing `FileStateSessionBackend` leads to Application Denial of Service and File Write/DeletionEPSS 0.7%CVE-2025-30358HIGHMesop Class Pollution vulnerability leads to DoS and Jailbreak attacksEPSS 0.7%CVE-2026-93421MEDIUMMesop: Unauthenticated ANSI Escape Sequence Injection in CSP Reporting EndpointEPSS 0.5%