CVE-2026-40567 (GCVE-0-2026-40567)

Vulnerability from cvelistv5 – Published: 2026-04-21 16:06 – Updated: 2026-04-21 19:17
VLAI
Title
FreeScout has HTML Injection in Outgoing Emails via Unsanitized Customer Name in Signature Variables
Summary
FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, an unauthenticated attacker can inject arbitrary HTML into outgoing emails generated by FreeScout by sending an email with a crafted From display name. The name is stored in the database without sanitization and rendered unescaped into outgoing reply emails via the `{%customer.fullName%}` signature variable. This allows embedding phishing links, tracking pixels, and spoofed content inside legitimate support emails sent from the organization's address. Version 1.8.213 fixes the issue.
Severity
5.8 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-116 - Improper Encoding or Escaping of Output
Assigner
References
Impacted products
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-40567",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-21T19:17:14.445574Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-21T19:17:33.873Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-q8v4-v62h-5528"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "freescout",
          "vendor": "freescout-help-desk",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.8.213"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, an unauthenticated attacker can inject arbitrary HTML into outgoing emails generated by FreeScout by sending an email with a crafted From display name. The name is stored in the database without sanitization and rendered unescaped into outgoing reply emails via the `{%customer.fullName%}` signature variable. This allows embedding phishing links, tracking pixels, and spoofed content inside legitimate support emails sent from the organization\u0027s address. Version 1.8.213 fixes the issue."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.8,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-116",
              "description": "CWE-116: Improper Encoding or Escaping of Output",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-21T16:06:39.878Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-q8v4-v62h-5528",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-q8v4-v62h-5528"
        },
        {
          "name": "https://github.com/freescout-help-desk/freescout/commit/9131b16f80eade81002cb9809a2603f6b61981cf",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/freescout-help-desk/freescout/commit/9131b16f80eade81002cb9809a2603f6b61981cf"
        },
        {
          "name": "https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213"
        }
      ],
      "source": {
        "advisory": "GHSA-q8v4-v62h-5528",
        "discovery": "UNKNOWN"
      },
      "title": "FreeScout has HTML Injection in Outgoing Emails via Unsanitized Customer Name in Signature Variables"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-40567",
    "datePublished": "2026-04-21T16:06:39.878Z",
    "dateReserved": "2026-04-14T13:24:29.474Z",
    "dateUpdated": "2026-04-21T19:17:33.873Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-40567",
      "date": "2026-06-04",
      "epss": "0.00066",
      "percentile": "0.20558"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-40567\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-04-21T17:16:55.153\",\"lastModified\":\"2026-04-22T21:10:14.290\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, an unauthenticated attacker can inject arbitrary HTML into outgoing emails generated by FreeScout by sending an email with a crafted From display name. The name is stored in the database without sanitization and rendered unescaped into outgoing reply emails via the `{%customer.fullName%}` signature variable. This allows embedding phishing links, tracking pixels, and spoofed content inside legitimate support emails sent from the organization\u0027s address. Version 1.8.213 fixes the issue.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N\",\"baseScore\":5.8,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":3.9,\"impactScore\":1.4}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-116\"}]}],\"references\":[{\"url\":\"https://github.com/freescout-help-desk/freescout/commit/9131b16f80eade81002cb9809a2603f6b61981cf\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-q8v4-v62h-5528\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-q8v4-v62h-5528\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\"}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-40567\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-04-21T19:17:14.445574Z\"}}}], \"references\": [{\"url\": \"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-q8v4-v62h-5528\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-04-21T19:17:30.844Z\"}}], \"cna\": {\"title\": \"FreeScout has HTML Injection in Outgoing Emails via Unsanitized Customer Name in Signature Variables\", \"source\": {\"advisory\": \"GHSA-q8v4-v62h-5528\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"CHANGED\", \"version\": \"3.1\", \"baseScore\": 5.8, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}], \"affected\": [{\"vendor\": \"freescout-help-desk\", \"product\": \"freescout\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 1.8.213\"}]}], \"references\": [{\"url\": \"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-q8v4-v62h-5528\", \"name\": \"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-q8v4-v62h-5528\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/freescout-help-desk/freescout/commit/9131b16f80eade81002cb9809a2603f6b61981cf\", \"name\": \"https://github.com/freescout-help-desk/freescout/commit/9131b16f80eade81002cb9809a2603f6b61981cf\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213\", \"name\": \"https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, an unauthenticated attacker can inject arbitrary HTML into outgoing emails generated by FreeScout by sending an email with a crafted From display name. The name is stored in the database without sanitization and rendered unescaped into outgoing reply emails via the `{%customer.fullName%}` signature variable. This allows embedding phishing links, tracking pixels, and spoofed content inside legitimate support emails sent from the organization\u0027s address. Version 1.8.213 fixes the issue.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-116\", \"description\": \"CWE-116: Improper Encoding or Escaping of Output\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-04-21T16:06:39.878Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-40567\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-04-21T19:17:33.873Z\", \"dateReserved\": \"2026-04-14T13:24:29.474Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-04-21T16:06:39.878Z\", \"assignerShortName\": \"GitHub_M\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.