{"id":"CVE-2026-48028","summary":"Mastodon: Removal of integrity-protected JSON entries from signed activities","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 threat actors to remove JSON entries from valid signed activities from a third-party actor. This vulnerability is fixed in 4.5.10, 4.4.17, and 4.3.23.","aliases":["BIT-mastodon-2026-48028","GHSA-53m7-2wrh-q839"],"modified":"2026-07-15T01:49:20.855609302Z","published":"2026-06-24T19:43:01.469Z","database_specific":{"cwe_ids":["CWE-354"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48028.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48028.json"},{"type":"ADVISORY","url":"https://github.com/mastodon/mastodon/security/advisories/GHSA-53m7-2wrh-q839"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48028"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mastodon/mastodon","events":[{"introduced":"5a8ab0a3e62a8825e28bb74c1760ba6488d20c97"},{"fixed":"f80b1ba92e63c3da771b405b9100f5c9abda909f"},{"introduced":"12c0e58d9aa80db570fba5fa5146f3a640e99b42"},{"fixed":"13b262a0c5ecba3cf10faca7eb193ca23b236af5"},{"introduced":"0"},{"fixed":"efb25b6aa2014201b04f25c390ad1f516a3ff52d"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"4.5.0-beta.1"},{"fixed":"4.5.10"},{"introduced":"4.4.0-beta.1"},{"fixed":"4.4.17"},{"introduced":"0"},{"fixed":"4.3.23"}]}}],"versions":["v4.4.16","v4.5.9","v4.3.22","v4.3.21","v4.4.15","v4.5.8","v4.3.20","v4.4.14","v4.5.7","v4.3.19","v4.5.6","v4.4.13","v4.3.18","v4.4.12","v4.5.5","v4.5.4","v4.4.11","v4.3.17","v4.5.3","v4.3.16","v4.4.10","v4.5.2","v4.4.9","v4.3.15","v4.5.1","v4.5.0","v4.4.8","v4.3.14","v4.5.0-rc.3","v4.5.0-rc.2","v4.5.0-rc.1","v4.5.0-beta.2","v4.4.7","v4.5.0-beta.1","v4.4.6","v4.4.5","v4.3.13","v4.3.12","v4.4.4","v4.3.11","v4.4.3","v4.3.10","v4.4.2","v4.4.1","v4.4.0","v4.3.9","v4.4.0-rc.1","v4.4.0-beta.2","v4.4.0-beta.1","v4.3.8","v4.3.7","v4.3.6","v4.3.5","v4.3.4","v4.3.3","v4.3.2","v4.3.1","v4.3.0","v4.3.0-rc.1","v4.3.0-beta.2","v4.3.0-beta.1","v4.2.0","v4.2.0-rc2","v4.2.0-rc1","v4.2.0-beta3","v4.2.0-beta2","v4.2.0-beta1","v4.0.2","v4.1.0","v4.1.0rc3","v4.1.0rc2","v4.1.0rc1","v4.0.1","v4.0.0","v4.0.0rc4","v3.5.3","v4.0.0rc3","v4.0.0rc2","v4.0.0rc1","v3.5.2","v3.5.1","v3.5.0","v3.5.0rc3","v3.5.0rc2","v3.5.0rc1","v3.3.0","v3.4.1","v3.4.0","v3.4.0rc2","v3.4.0rc1","v3.3.0rc3","v3.3.0rc2","v3.3.0rc1","v3.2.0","v3.2.0rc2","v3.2.0rc1","v3.1.4","v3.1.3","v3.1.2","v3.0.1","v3.1.1","v3.1.0","v3.1.0rc2","v3.1.0rc1","v3.0.0","v3.0.0rc3","v3.0.0rc2","v3.0.0rc1","v2.9.2","v2.9.1","v2.9.0","v2.9.0rc2","v2.9.0rc1","v2.8.2","v2.8.1","v2.8.0","v2.8.0rc3","v2.8.0rc2","v2.8.0rc1","v2.7.1","v2.7.0","v2.7.0rc3","v2.7.0rc2","v2.7.0rc1","v2.6.1","v2.6.0","v2.6.0rc4","v2.6.0rc3","v2.6.0rc2","v2.6.0rc1","v2.5.0","v2.5.0rc2","v2.5.0rc1","v2.4.3","v2.4.3rc3","v2.4.3rc2","v2.4.3rc1","v2.4.2","v2.4.2rc3","v2.4.2rc2","v2.4.2rc1","v2.4.1","v2.4.1rc4","v2.4.1rc3","v2.4.1rc2","v2.4.1rc1","v2.4.0","v2.4.0rc5","v2.4.0rc4","v2.4.0rc3","v2.4.0rc2","v2.4.0rc1","v2.3.2","v2.3.2rc5","v2.3.2rc4","v2.3.2rc3","v2.3.2rc2","v2.3.2rc1","v2.3.1","v2.3.1rc3","v2.3.1rc2","v2.3.1rc1","v2.3.0","v2.3.0rc3","v2.3.0rc2","v2.3.0rc1","v2.2.0","v2.2.0rc2","v2.2.0rc1","v2.1.3","v2.1.2","v2.1.1","v2.1.0","v2.1.0rc6","v2.1.0rc5","v2.1.0rc4","v2.1.0rc3","v2.1.0rc2","v2.1.0rc1","v2.0.0","v2.0.0rc4","v2.0.0rc3","v2.0.0rc2","v2.0.0rc1","v1.6.1","v1.6.0","v1.6.0rc5","v1.6.0rc4","v1.6.0rc3","v1.6.0rc2","v1.6.0rc1","v1.5.1","v1.5.0","v1.5.0rc3","v1.5.0rc2","v1.5.0rc1","v1.4.7","v1.4.6","v1.4.5","v1.4.4","v1.4.3","v1.4.2","v1.4.1","v1.4rc6","v1.4rc5","v1.4rc4","v1.4rc3","v1.4rc2","v1.4rc1","v1.3.2","v1.3.1","v1.3","v1.2.2","v1.2.1","v1.2","v1.1.2","v1.1.1","v1.1","v1.0","v0.9.9","v0.9","v0.8","v0.7","v0.6","v0.1.2","v0.1.1","v0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48028.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L"}]}