{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-42462: Fedify has an LD-Signature Bypass via JSON-LD Named-Graph Restructuring","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-42462","status":"final","version":"1","initial_release_date":"2026-06-10T20:22:35.383Z","current_release_date":"2026-06-11T13:34:03.443Z","revision_history":[{"date":"2026-06-10T20:22:35.383Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"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.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-42462 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-42462"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-42462"},{"category":"external","summary":"https://github.com/fedify-dev/fedify/security/advisories/GHSA-9rfg-v8g9-9367","url":"https://github.com/fedify-dev/fedify/security/advisories/GHSA-9rfg-v8g9-9367"},{"category":"external","summary":"https://github.com/fedify-dev/fedify/releases/tag/2.2.3","url":"https://github.com/fedify-dev/fedify/releases/tag/2.2.3"}]},"product_tree":{"branches":[{"category":"vendor","name":"fedify-dev","branches":[{"category":"product_name","name":"fedify","branches":[{"category":"product_version","name":">= 2.2.0, < 2.2.3","product":{"name":"fedify-dev fedify >= 2.2.0, < 2.2.3","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:fedify-dev:fedify:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":">= 2.1.0, < 2.1.14","product":{"name":"fedify-dev fedify >= 2.1.0, < 2.1.14","product_id":"CSAFPID-2","product_identification_helper":{"cpe":"cpe:2.3:a:fedify-dev:fedify:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":">= 2.0.0, < 2.0.18","product":{"name":"fedify-dev fedify >= 2.0.0, < 2.0.18","product_id":"CSAFPID-3","product_identification_helper":{"cpe":"cpe:2.3:a:fedify-dev:fedify:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":">= 1.10.0, < 1.10.10","product":{"name":"fedify-dev fedify >= 1.10.0, < 1.10.10","product_id":"CSAFPID-4","product_identification_helper":{"cpe":"cpe:2.3:a:fedify-dev:fedify:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"< 1.9.11","product":{"name":"fedify-dev fedify < 1.9.11","product_id":"CSAFPID-5","product_identification_helper":{"cpe":"cpe:2.3:a:fedify-dev:fedify:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-42462","title":"Fedify has an LD-Signature Bypass via JSON-LD Named-Graph Restructuring","notes":[{"category":"description","text":"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.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4","CSAFPID-5"]},"scores":[{"cvss_v3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L","baseScore":7,"baseSeverity":"HIGH"},"products":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4","CSAFPID-5"]}],"remediations":[{"category":"none_available","details":"No fixed version is published yet. Monitor the upstream advisory.","product_ids":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4","CSAFPID-5"]}]}]}