Vulnerability-Lookup

Vulnerability from bitnami_vulndb

Published

2026-07-06 05:55

Modified

2026-07-06 06:18

Summary

Mastodon: LD-Signature Bypass via JSON-LD Named-Graph Restructuring

Details

Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, Mastodon's normalization of incoming activities signed with Linked-Data Signatures does not sufficiently protect the activities from a certain class of spoofing, allowing attackers to re-arrange a valid signed JSON-LD activity from a third-party actor to have it processed differently. This vulnerability is fixed in 4.5.10, 4.4.17, and 4.3.23.

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "mastodon",
        "purl": "pkg:bitnami/mastodon"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.5.0"
            },
            {
              "fixed": "4.5.10"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-46349"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*"
    ],
    "severity": "Medium"
  },
  "details": "Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, Mastodon\u0027s normalization of incoming activities signed with Linked-Data Signatures does not sufficiently protect the activities from a certain class of spoofing, allowing attackers to re-arrange a valid signed JSON-LD activity from a third-party actor to have it processed differently. This vulnerability is fixed in 4.5.10, 4.4.17, and 4.3.23.",
  "id": "BIT-mastodon-2026-46349",
  "modified": "2026-07-06T06:18:57.499Z",
  "published": "2026-07-06T05:55:15.922Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/mastodon/mastodon/security/advisories/GHSA-chgx-jx3p-rf73"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46349"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Mastodon: LD-Signature Bypass via JSON-LD Named-Graph Restructuring"
}

CVE-2026-46349 (GCVE-0-2026-46349)

Vulnerability from cvelistv5 – Published: 2026-06-24 19:40 – Updated: 2026-06-25 13:16

Title

Mastodon: LD-Signature Bypass via JSON-LD Named-Graph Restructuring

Summary

Severity

5.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-347 - Improper Verification of Cryptographic Signature

Assigner

GitHub_M

References

1 reference

URL	Tags
https://github.com/mastodon/mastodon/security/adv…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
mastodon	mastodon	Affected: >= 4.5.0-beta.1, < 4.5.10

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-46349",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-25T13:16:40.328930Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-25T13:16:49.851Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "mastodon",
          "vendor": "mastodon",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 4.5.0-beta.1, \u003c 4.5.10"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, Mastodon\u0027s normalization of incoming activities signed with Linked-Data Signatures does not sufficiently protect the activities from a certain class of spoofing, allowing attackers to re-arrange a valid signed JSON-LD activity from a third-party actor to have it processed differently. This vulnerability is fixed in 4.5.10, 4.4.17, and 4.3.23."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-347",
              "description": "CWE-347: Improper Verification of Cryptographic Signature",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-24T19:40:35.022Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/mastodon/mastodon/security/advisories/GHSA-chgx-jx3p-rf73",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/mastodon/mastodon/security/advisories/GHSA-chgx-jx3p-rf73"
        }
      ],
      "source": {
        "advisory": "GHSA-chgx-jx3p-rf73",
        "discovery": "UNKNOWN"
      },
      "title": "Mastodon: LD-Signature Bypass via JSON-LD Named-Graph Restructuring"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-46349",
    "datePublished": "2026-06-24T19:40:35.022Z",
    "dateReserved": "2026-05-13T18:37:30.990Z",
    "dateUpdated": "2026-06-25T13:16:49.851Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Action not permitted

Vulnerability from bitnami_vulndb

CVE-2026-46349 (GCVE-0-2026-46349)

Tags

Sightings

Nomenclature