{"id":"CVE-2026-42462","aliases":["GHSA-9rfg-v8g9-9367"],"url":"https://o3.security/vulnerability/CVE-2026-42462","summary":"Fedify has an LD-Signature Bypass via JSON-LD Named-Graph Restructuring","details":"Fedify is a TypeScript library for building federated server apps powered by ActivityPub. Prior to versions 1.9.11, 1.10.10, 2.0.18, 2.1.14, and 2.2.3, an attacker can make use of JSON-LD features to restructure a JSON-LD document that would change how Fedify interprets it without changing its Linked Data Signature, allowing them to alter a third-party signed activity they have received. Versions 1.9.11, 1.10.10, 2.0.18, 2.1.14, and 2.2.3 fix the issue.","published":"2026-06-10T20:22:35.383Z","modified":"2026-08-12T03:51:45.403995058Z","cvss":{"score":7,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L"},"epss":{"score":0.00171,"percentile":0.06692,"asOf":"2026-08-10"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@fedify/fedify","fixedVersion":"2.2.3"},{"ecosystem":"npm","name":"@fedify/fedify","fixedVersion":"2.1.14"},{"ecosystem":"npm","name":"@fedify/fedify","fixedVersion":"2.0.18"},{"ecosystem":"npm","name":"@fedify/fedify","fixedVersion":"1.10.10"},{"ecosystem":"npm","name":"@fedify/fedify","fixedVersion":"1.9.11"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/fedify-dev/fedify/releases/tag/2.2.3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42462.json"},{"type":"ADVISORY","url":"https://github.com/fedify-dev/fedify/security/advisories/GHSA-9rfg-v8g9-9367"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42462"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:45.403995058Z"}}