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FKIE_CVE-2026-53591

Vulnerability from fkie_nvd - Published: 2026-07-20 20:16 - Updated: 2026-07-21 19:25
Severity
8.6 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
Summary
FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.223, an unauthenticated attacker can inject messages into any existing support conversation by sending a single email to the helpdesk's public address with a crafted `In-Reply-To` header. No credentials, tokens, or prior access are required. The injected message is rendered in the agent UI as a legitimate customer reply, the conversation is automatically reopened, and the `last_reply_from` field is set to the attacker's identity. Version 1.8.223 contains a fix.
References
security-advisories@github.comhttps://github.com/freescout-help-desk/freescout/security/advisories/GHSA-8vm3-wwq4-ggfx
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-8vm3-wwq4-ggfx
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "freescout",
          "vendor": "freescout-help-desk",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.8.223"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "FreeScout is a free help desk and shared inbox built with PHP\u0027s Laravel framework. Prior to version 1.8.223, an unauthenticated attacker can inject messages into any existing support conversation by sending a single email to the helpdesk\u0027s public address with a crafted `In-Reply-To` header. No credentials, tokens, or prior access are required. The injected message is rendered in the agent UI as a legitimate customer reply, the conversation is automatically reopened, and the `last_reply_from` field is set to the attacker\u0027s identity. Version 1.8.223 contains a fix."
    }
  ],
  "id": "CVE-2026-53591",
  "lastModified": "2026-07-21T19:25:11.717",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 8.6,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "LOW",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 4.7,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-53591",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-20T20:15:06.613729Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-20T20:16:44.613",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-8vm3-wwq4-ggfx"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-8vm3-wwq4-ggfx"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-287"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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