FKIE_CVE-2026-77357

Vulnerability from fkie_nvd - Published: 2026-08-25 21:17 - Updated: 2026-08-26 14:17
Severity
8.7 (High) - 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
Summary
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.
References
security-advisories@github.comhttps://github.com/mesop-dev/mesop/commit/2b8e7f2c349c9e2eec202f46b07bada83061ce2d
security-advisories@github.comhttps://github.com/mesop-dev/mesop/releases/tag/v1.3.3
security-advisories@github.comhttps://github.com/mesop-dev/mesop/security/advisories/GHSA-8p72-497j-83mx
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "mesop",
          "vendor": "mesop-dev",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.3.3"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "id": "CVE-2026-77357",
  "lastModified": "2026-08-26T14:17:13.883",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 8.7,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-77357",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-26T12:53:16.316229Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-25T21:17:46.090",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/mesop-dev/mesop/commit/2b8e7f2c349c9e2eec202f46b07bada83061ce2d"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/mesop-dev/mesop/releases/tag/v1.3.3"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/mesop-dev/mesop/security/advisories/GHSA-8p72-497j-83mx"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        },
        {
          "lang": "en",
          "value": "CWE-834"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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