FKIE_CVE-2026-22245

Vulnerability from fkie_nvd - Published: 2026-01-08 16:16 - Updated: 2026-01-15 20:36
Severity ?
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Summary
Mastodon is a free, open-source social network server based on ActivityPub. By nature, Mastodon performs a lot of outbound requests to user-provided domains. Mastodon, however, has some protection mechanism to disallow requests to local IP addresses (unless specified in `ALLOWED_PRIVATE_ADDRESSES`) to avoid the "confused deputy" problem. The list of disallowed IP address ranges was lacking some IP address ranges that can be used to reach local IP addresses. An attacker can use an IP address in the affected ranges to make Mastodon perform HTTP requests against loopback or local network hosts, potentially allowing access to otherwise private resources and services. This is fixed in Mastodon v4.5.4, v4.4.11, v4.3.17 and v4.2.29.
References
security-advisories@github.comhttps://github.com/mastodon/mastodon/commit/0f4e8a6240b5af1f2c3f34d2793d8610c6ef2acaPatch
security-advisories@github.comhttps://github.com/mastodon/mastodon/commit/17022907866710a72a1b1fc0a5ce9538bad1b4c3Patch
security-advisories@github.comhttps://github.com/mastodon/mastodon/commit/71ae4cf2cf5138ccdda64b1b1d665849b688686dPatch
security-advisories@github.comhttps://github.com/mastodon/mastodon/security/advisories/GHSA-xfrj-c749-jxxqVendor Advisory
Impacted products
Vendor Product Version
joinmastodon mastodon *
joinmastodon mastodon *
joinmastodon mastodon *
joinmastodon mastodon *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "9DC30BD1-D8D8-4CA4-AC41-1AA95AADDBD3",
              "versionEndExcluding": "4.2.29",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "DEAC34A7-EB88-4E46-B5D6-F4EBB88CE049",
              "versionEndExcluding": "4.3.17",
              "versionStartIncluding": "4.3.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "DD92863A-CB76-45AA-BF4D-9870B24E8109",
              "versionEndExcluding": "4.4.11",
              "versionStartIncluding": "4.4.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "3E8FBAF5-C7BC-4980-9780-50BA935D126B",
              "versionEndExcluding": "4.5.4",
              "versionStartIncluding": "4.5.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Mastodon is a free, open-source social network server based on ActivityPub. By nature, Mastodon performs a lot of outbound requests to user-provided domains. Mastodon, however, has some protection mechanism to disallow requests to local IP addresses (unless specified in `ALLOWED_PRIVATE_ADDRESSES`) to avoid the \"confused deputy\" problem. The list of disallowed IP address ranges was lacking some IP address ranges that can be used to reach local IP addresses. An attacker can use an IP address in the affected ranges to make Mastodon perform HTTP requests against loopback or local network hosts, potentially allowing access to otherwise private resources and services. This is fixed in Mastodon v4.5.4, v4.4.11, v4.3.17 and v4.2.29."
    },
    {
      "lang": "es",
      "value": "Mastodon es un servidor de red social gratuito, de c\u00f3digo abierto, basado en ActivityPub. Por naturaleza, Mastodon realiza muchas solicitudes salientes a dominios proporcionados por el usuario. Mastodon, sin embargo, tiene alg\u00fan mecanismo de protecci\u00f3n para denegar solicitudes a direcciones IP locales (a menos que se especifique en \u0027ALLOWED_PRIVATE_ADDRESSES\u0027) para evitar el problema del \u0027diputado confundido\u0027. La lista de rangos de direcciones IP no permitidas carec\u00eda de algunos rangos de direcciones IP que pueden usarse para alcanzar direcciones IP locales. Un atacante puede usar una direcci\u00f3n IP en los rangos afectados para hacer que Mastodon realice solicitudes HTTP contra hosts de bucle invertido o de red local, lo que podr\u00eda permitir el acceso a recursos y servicios que de otro modo ser\u00edan privados. Esto est\u00e1 corregido en Mastodon v4.5.4, v4.4.11, v4.3.17 y v4.2.29."
    }
  ],
  "id": "CVE-2026-22245",
  "lastModified": "2026-01-15T20:36:42.153",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 7.1,
          "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": "LOW",
          "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:L/UI:N/VC:N/VI:H/VA:N/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": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-01-08T16:16:02.803",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/mastodon/mastodon/commit/0f4e8a6240b5af1f2c3f34d2793d8610c6ef2aca"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
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      "url": "https://github.com/mastodon/mastodon/commit/17022907866710a72a1b1fc0a5ce9538bad1b4c3"
    },
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      "source": "security-advisories@github.com",
      "tags": [
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    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://github.com/mastodon/mastodon/security/advisories/GHSA-xfrj-c749-jxxq"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}


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  • 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.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.