FKIE_CVE-2026-42209

Vulnerability from fkie_nvd - Published: 2026-05-08 22:16 - Updated: 2026-05-13 16:52
Severity
6.5 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
FlashMQ is a MQTT broker/server, designed for multi-CPU environments. Prior to version 1.26.1, a remote client with retained publish permission can crash the FlashMQ broker when both set_retained_message_defer_timeout and set_retained_message_defer_timeout_spread are configured to non-default values, resulting in denial of service. If anonymous retained publishing is allowed, no authentication is required; otherwise, the attacker needs the corresponding publish permission. This issue has been patched in version 1.26.1.
References
security-advisories@github.comhttps://github.com/halfgaar/FlashMQ/commit/193b6e7767889511cfa8e933908ea5e6a1077a1f
security-advisories@github.comhttps://github.com/halfgaar/FlashMQ/issues/167
security-advisories@github.comhttps://github.com/halfgaar/FlashMQ/releases/tag/v1.26.1
security-advisories@github.comhttps://github.com/halfgaar/FlashMQ/security/advisories/GHSA-2789-vfcg-5922
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/halfgaar/FlashMQ/issues/167
Impacted products
Vendor Product Version
To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "FlashMQ is a MQTT broker/server, designed for multi-CPU environments. Prior to version 1.26.1, a remote client with retained publish permission can crash the FlashMQ broker when both set_retained_message_defer_timeout and set_retained_message_defer_timeout_spread are configured to non-default values, resulting in denial of service. If anonymous retained publishing is allowed, no authentication is required; otherwise, the attacker needs the corresponding publish permission. This issue has been patched in version 1.26.1."
    }
  ],
  "id": "CVE-2026-42209",
  "lastModified": "2026-05-13T16:52:48.773",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-05-08T22:16:32.103",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/halfgaar/FlashMQ/commit/193b6e7767889511cfa8e933908ea5e6a1077a1f"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/halfgaar/FlashMQ/issues/167"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/halfgaar/FlashMQ/releases/tag/v1.26.1"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/halfgaar/FlashMQ/security/advisories/GHSA-2789-vfcg-5922"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/halfgaar/FlashMQ/issues/167"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-369"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}


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