{"id":"CVE-2026-53950","aliases":["BIT-ghost-2026-53950","EUVD-2026-39019","GHSA-xpp7-93x6-v29m"],"status":"published","title":"@tryghost/activitypub: XSS in Ghost's ActivityPub client","description":"@tryghost/activitypub is Ghost’s social/federation client app. Prior to 3.1.0, the ActivityPub client in Ghost was vulnerable to JavaScript injection on posts shared by a maliciously customised ActivityPub server. This vulnerability is fixed in 3.1.0.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00352,"percentile":0.29173,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-79"],"published":"2026-06-24T18:04:25Z","modified":"2026-10-28T02:30:28Z","fixes":[{"ecosystem":"npm","package":"@tryghost/activitypub","fixed_in":["3.1.0"],"sources":["ghsa","osv"]},{"ecosystem":"Bitnami","package":"ghost","fixed_in":["3.1.0"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"@tryghost/activitypub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.1.0"}]}]},{"source":"osv","ecosystem":"Bitnami","package":"ghost","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.1.0"}]}]},{"source":"osv","ecosystem":"npm","package":"@tryghost/activitypub","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.1.0"}]}]}],"products":[{"vendor":"tryghost","product":"ghost"}],"references":[{"url":"https://github.com/TryGhost/Ghost/security/advisories/GHSA-xpp7-93x6-v29m","tags":["x_refsource_CONFIRM","web","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53950","tags":["web","advisory"]},{"url":"https://github.com/advisories/GHSA-xpp7-93x6-v29m"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53950.json","tags":["advisory"]},{"url":"https://github.com/TryGhost/Ghost","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-53950","title":"@tryghost/activitypub: XSS in Ghost's ActivityPub client","description":"@tryghost/activitypub is Ghost’s social/federation client app. Prior to 3.1.0, the ActivityPub client in Ghost was vulnerable to JavaScript injection on posts shared by a maliciously customised ActivityPub server. This vulnerability is fixed in 3.1.0.","status":"published","published":"2026-06-24T18:04:25.695Z","modified":"2026-06-24T18:49:55.01Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:20:00.11477Z"}],"euvd":[{"id":"EUVD-2026-39019","description":"@tryghost/activitypub is Ghost’s social/federation client app. Prior to 3.1.0, the ActivityPub client in Ghost was vulnerable to JavaScript injection on posts shared by a maliciously customised ActivityPub server. This vulnerability is fixed in 3.1.0.","status":"published","published":"2026-06-24T18:04:25Z","modified":"2026-06-24T18:49:55Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T18:20:30.242414Z"}],"ghsa":[{"id":"GHSA-xpp7-93x6-v29m","title":"XSS in Ghost's ActivityPub client","description":"### Impact\n\nThe ActivityPub client in Ghost was vulnerable to JavaScript injection on posts shared by a maliciously customised ActivityPub server.\n\n### Vulnerable Versions\n\nThis vulnerability is present in the @tryghost/activitypub package up to v3.0.8. All prior versions are also affected. \n\n### Patches\n\n@tryghost/activitypub v3.1.0 contains a fix for this issue and is also automatically fetched by Ghost.\n\n### References\n\nGhost thanks Brad Geesaman, Ghost Security for disclosing this vulnerability responsibly. \n\n### For more information\n\nIf you have any questions or comments about this advisory, email Ghost at [security@ghost.org](mailto:security@ghost.org).","status":"published","published":"2026-08-04T21:54:01Z","modified":"2026-08-04T21:54:01Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:40:56.852119Z"}],"nvd":[{"id":"CVE-2026-53950","description":"@tryghost/activitypub is Ghost’s social/federation client app. Prior to 3.1.0, the ActivityPub client in Ghost was vulnerable to JavaScript injection on posts shared by a maliciously customised ActivityPub server. This vulnerability is fixed in 3.1.0.","status":"published","published":"2026-06-24T19:17:12.713Z","modified":"2026-10-25T22:10:00.15Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:25.67873Z"}],"osv":[{"id":"CVE-2026-53950","title":"@tryghost/activitypub: XSS in Ghost's ActivityPub client","description":"@tryghost/activitypub is Ghost’s social/federation client app. Prior to 3.1.0, the ActivityPub client in Ghost was vulnerable to JavaScript injection on posts shared by a maliciously customised ActivityPub server. This vulnerability is fixed in 3.1.0.","status":"published","published":"2026-06-24T18:04:25.695Z","modified":"2026-10-28T02:30:28.97876536Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:45:08.132336Z"},{"id":"GHSA-xpp7-93x6-v29m","title":"XSS in Ghost's ActivityPub client","description":"### Impact\n\nThe ActivityPub client in Ghost was vulnerable to JavaScript injection on posts shared by a maliciously customised ActivityPub server.\n\n### Vulnerable Versions\n\nThis vulnerability is present in the @tryghost/activitypub package up to v3.0.8. All prior versions are also affected. \n\n### Patches\n\n@tryghost/activitypub v3.1.0 contains a fix for this issue and is also automatically fetched by Ghost.\n\n### References\n\nGhost thanks Brad Geesaman, Ghost Security for disclosing this vulnerability responsibly. \n\n### For more information\n\nIf you have any questions or comments about this advisory, email Ghost at [security@ghost.org](mailto:security@ghost.org).","status":"published","published":"2026-08-04T21:54:01Z","modified":"2026-08-04T22:00:24.156211177Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:47:00.198893Z"},{"id":"BIT-ghost-2026-53950","title":"@tryghost/activitypub: XSS in Ghost's ActivityPub client","description":"@tryghost/activitypub is Ghost’s social/federation client app. Prior to 3.1.0, the ActivityPub client in Ghost was vulnerable to JavaScript injection on posts shared by a maliciously customised ActivityPub server. This vulnerability is fixed in 3.1.0.","status":"published","published":"2026-06-30T23:39:27.609Z","modified":"2026-07-08T08:11:30.819999995Z","updated_at":"2026-11-02T15:28:29.999658Z"}]}}