CVE-2026-52840 (GCVE-0-2026-52840)

Vulnerability from cvelistv5 – Published: 2026-07-14 15:23 – Updated: 2026-07-15 13:53
VLAI
Title
Easy!Appointments has server-side request forgery in CalDAV connection test that exposes the deployment's internal network
Summary
Easy!Appointments is a self hosted appointment scheduler. In versions prior to 1.6.0, `Caldav::connect_to_server` at `application/controllers/Caldav.php:60` hands the request's `caldav_url` to a Guzzle `REPORT` call without scheme or host validation. A logged-in backend user (admin, provider, or secretary) reaches loopback, RFC1918, and link-local hosts on the deployment's network. The Guzzle exception path returns the upstream status code plus ~120 bytes of response body in the JSON `message` field (`Caldav.php:74-78`), so the SSRF is semi-blind. Version 1.6.0 contains a patch.
Severity
2.7 (Low)
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-918 - Server-Side Request Forgery (SSRF)
Assigner
References
Impacted products
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-52840",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-15T13:53:03.540827Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-15T13:53:09.948Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-pm5p-7w5h-jm5q"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "easyappointments",
          "vendor": "alextselegidis",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.6.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Easy!Appointments is a self hosted appointment scheduler. In versions prior to 1.6.0, `Caldav::connect_to_server` at `application/controllers/Caldav.php:60` hands the request\u0027s `caldav_url` to a Guzzle `REPORT` call without scheme or host validation. A logged-in backend user (admin, provider, or secretary) reaches loopback, RFC1918, and link-local hosts on the deployment\u0027s network. The Guzzle exception path returns the upstream status code plus ~120 bytes of response body in the JSON `message` field (`Caldav.php:74-78`), so the SSRF is semi-blind. Version 1.6.0 contains a patch."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 2.7,
            "baseSeverity": "LOW",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "HIGH",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-918",
              "description": "CWE-918: Server-Side Request Forgery (SSRF)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-14T15:23:59.992Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-pm5p-7w5h-jm5q",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-pm5p-7w5h-jm5q"
        },
        {
          "name": "https://github.com/alextselegidis/easyappointments/commit/6eb9336a91cfb276379506625e81f5bd9ed3a536",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/alextselegidis/easyappointments/commit/6eb9336a91cfb276379506625e81f5bd9ed3a536"
        }
      ],
      "source": {
        "advisory": "GHSA-pm5p-7w5h-jm5q",
        "discovery": "UNKNOWN"
      },
      "title": "Easy!Appointments has server-side request forgery in CalDAV connection test that exposes the deployment\u0027s internal network"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-52840",
    "datePublished": "2026-07-14T15:23:59.992Z",
    "dateReserved": "2026-06-08T18:41:27.724Z",
    "dateUpdated": "2026-07-15T13:53:09.948Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-52840",
      "date": "2026-07-15",
      "epss": "0.00186",
      "percentile": "0.08367"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-52840\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-07-14T16:17:00.670\",\"lastModified\":\"2026-07-15T14:18:23.000\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Easy!Appointments is a self hosted appointment scheduler. In versions prior to 1.6.0, `Caldav::connect_to_server` at `application/controllers/Caldav.php:60` hands the request\u0027s `caldav_url` to a Guzzle `REPORT` call without scheme or host validation. A logged-in backend user (admin, provider, or secretary) reaches loopback, RFC1918, and link-local hosts on the deployment\u0027s network. The Guzzle exception path returns the upstream status code plus ~120 bytes of response body in the JSON `message` field (`Caldav.php:74-78`), so the SSRF is semi-blind. Version 1.6.0 contains a patch.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"alextselegidis\",\"product\":\"easyappointments\",\"versions\":[{\"version\":\"\u003c 1.6.0\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N\",\"baseScore\":2.7,\"baseSeverity\":\"LOW\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"HIGH\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":1.2,\"impactScore\":1.4}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-07-15T13:53:03.540827Z\",\"id\":\"CVE-2026-52840\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-918\"}]}],\"references\":[{\"url\":\"https://github.com/alextselegidis/easyappointments/commit/6eb9336a91cfb276379506625e81f5bd9ed3a536\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-pm5p-7w5h-jm5q\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-pm5p-7w5h-jm5q\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\"}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-52840\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-07-15T13:53:03.540827Z\"}}}], \"references\": [{\"url\": \"https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-pm5p-7w5h-jm5q\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-07-15T13:52:52.557Z\"}}], \"cna\": {\"title\": \"Easy!Appointments has server-side request forgery in CalDAV connection test that exposes the deployment\u0027s internal network\", \"source\": {\"advisory\": \"GHSA-pm5p-7w5h-jm5q\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 2.7, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"LOW\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"HIGH\", \"confidentialityImpact\": \"LOW\"}}], \"affected\": [{\"vendor\": \"alextselegidis\", \"product\": \"easyappointments\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 1.6.0\"}]}], \"references\": [{\"url\": \"https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-pm5p-7w5h-jm5q\", \"name\": \"https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-pm5p-7w5h-jm5q\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/alextselegidis/easyappointments/commit/6eb9336a91cfb276379506625e81f5bd9ed3a536\", \"name\": \"https://github.com/alextselegidis/easyappointments/commit/6eb9336a91cfb276379506625e81f5bd9ed3a536\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Easy!Appointments is a self hosted appointment scheduler. In versions prior to 1.6.0, `Caldav::connect_to_server` at `application/controllers/Caldav.php:60` hands the request\u0027s `caldav_url` to a Guzzle `REPORT` call without scheme or host validation. A logged-in backend user (admin, provider, or secretary) reaches loopback, RFC1918, and link-local hosts on the deployment\u0027s network. The Guzzle exception path returns the upstream status code plus ~120 bytes of response body in the JSON `message` field (`Caldav.php:74-78`), so the SSRF is semi-blind. Version 1.6.0 contains a patch.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-918\", \"description\": \"CWE-918: Server-Side Request Forgery (SSRF)\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-07-14T15:23:59.992Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-52840\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-07-15T13:53:09.948Z\", \"dateReserved\": \"2026-06-08T18:41:27.724Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-07-14T15:23:59.992Z\", \"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.