{"id":"CVE-2026-48028","aliases":["BIT-mastodon-2026-48028","EUVD-2026-39056","GHSA-53m7-2wrh-q839"],"status":"published","title":"Mastodon: Removal of integrity-protected JSON entries from signed activities","description":"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.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00176,"percentile":0.07126,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-354"],"published":"2026-06-24T19:43:01Z","modified":"2026-10-28T02:30:30Z","fixes":[{"ecosystem":"Bitnami","package":"mastodon","fixed_in":["4.3.23","4.4.17","4.5.10"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Bitnami","package":"mastodon","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"4.3.23"},{"introduced":"4.4.0"},{"fixed":"4.4.17"},{"introduced":"4.5.0"},{"fixed":"4.5.10"}]}]}],"products":[{"vendor":"mastodon","product":"mastodon"}],"references":[{"url":"https://github.com/mastodon/mastodon/security/advisories/GHSA-53m7-2wrh-q839","tags":["x_refsource_CONFIRM","web","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48028","tags":["web","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48028.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-48028","title":"Mastodon: Removal of integrity-protected JSON entries from signed activities","description":"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.","status":"published","published":"2026-06-24T19:43:01.469Z","modified":"2026-06-25T13:26:34.764Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T14:19:47.998488Z"}],"euvd":[{"id":"EUVD-2026-39056","description":"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.","status":"published","published":"2026-06-24T19:43:01Z","modified":"2026-06-25T13:26:34Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium"}],"updated_at":"2026-11-02T18:20:29.213001Z"}],"nvd":[{"id":"CVE-2026-48028","description":"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.","status":"published","published":"2026-06-24T20:16:32.787Z","modified":"2026-06-25T16:32:07.257Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T14:12:25.67873Z"}],"osv":[{"id":"CVE-2026-48028","title":"Mastodon: Removal of integrity-protected JSON entries from signed activities","description":"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.","status":"published","published":"2026-06-24T19:43:01.469Z","modified":"2026-10-28T02:30:30.35073219Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T15:45:06.701612Z"},{"id":"BIT-mastodon-2026-48028","title":"Mastodon: Removal of integrity-protected JSON entries from signed activities","description":"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.","status":"published","published":"2026-07-06T05:55:20.384Z","modified":"2026-07-08T08:11:10.561053549Z","updated_at":"2026-11-02T15:28:32.645004Z"}]}}