CVE-2026-57167

PeerTube is an ActivityPub-federated video streaming platform. Prior to 8.2.2, server-side-rendered video watch pages embed a schema.org JSON-LD block by JSON.stringify-ing video metadata without escaping less-than, greater-than, or slash characters, allowing a value containing the byte sequence...

EUVD-2026-42952

PeerTube is an ActivityPub-federated video streaming platform. Prior to 8.2.2, server-side-rendered video watch pages embed a schema.org JSON-LD block by JSON.stringify-ing video metadata without escaping less-than, greater-than, or slash characters, allowing a value containing the byte sequence...

GHSA-VW42-752G-5MRP YesWiki has Unauthenticated Server-Side Request Forgery via ActivityPub `Signature.keyId`

Summary The POST /api/forms/formId/actor/inbox route - exposed publicly with acl:"public" - accepts an HTTP Signature header whose keyId parameter is a URL. HttpSignatureService::verifySignature parses the header and immediately makes a server-side HTTP GET to that URL, before any cryptographic...

GHSA-MV28-WJ57-F57G YesWiki Vulnerable to Unauthenticated ActivityPub Signature-Verification Bypass via `!openssl_verify(...)` accepting `int(-1)`

Summary HttpSignatureService::verifySignature checks the result of PHP's opensslverify with a loose boolean negation - if !opensslverify... throw ... . PHP's opensslverify has four possible return values: | return | meaning | !return | | ------ | ------------------------------------------------ |...

BIT-MASTODON-2026-48028 Mastodon: Removal of integrity-protected JSON entries from signed activities

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...

CVE-2026-6902

creationtimestamp| type| source ---|---|--- 2026-07-02 15:13:56+00:00| seen| https://bsky.app/profile/2rZiKKbOU3nTafniR2qMMSE0gwZ.activitypub.awakari.com.ap.brid.gy/post/3mpod2scxtv72...

CVE-2026-58593

NodeBB does not bind the claimed author of an inbound ActivityPub object to the authenticated remote actor. The inbound middleware verifies the HTTP-signature actor and checks the origin of object.id, but never validates that attributedTo corresponds to the sender. In the object mock, attributedT...

CVE-2026-58593 NodeBB - ActivityPub Author Spoofing via Unvalidated attributedTo Mapped to Local User

NodeBB does not bind the claimed author of an inbound ActivityPub object to the authenticated remote actor. The inbound middleware verifies the HTTP-signature actor and checks the origin of object.id, but never validates that attributedTo corresponds to the sender. In the object mock, attributedT...

EUVD-2026-41131

NodeBB does not bind the claimed author of an inbound ActivityPub object to the authenticated remote actor. The inbound middleware verifies the HTTP-signature actor and checks the origin of object.id, but never validates that attributedTo corresponds to the sender. In the object mock, attributedT...

CVE-2026-58593

NodeBB does not bind the claimed author of an inbound ActivityPub object to the authenticated remote actor. The inbound middleware verifies the HTTP-signature actor and checks the origin of object.id, but never validates that attributedTo corresponds to the sender. In the object mock, attributedT...

CVE-2026-58593 NodeBB - ActivityPub Author Spoofing via Unvalidated attributedTo Mapped to Local User

NodeBB does not bind the claimed author of an inbound ActivityPub object to the authenticated remote actor. The inbound middleware verifies the HTTP-signature actor and checks the origin of object.id, but never validates that attributedTo corresponds to the sender. In the object mock, attributedT...

CVE-2026-58593 NodeBB - ActivityPub Author Spoofing via Unvalidated attributedTo Mapped to Local User

NodeBB does not bind the claimed author of an inbound ActivityPub object to the authenticated remote actor. The inbound middleware verifies the HTTP-signature actor and checks the origin of object.id, but never validates that attributedTo corresponds to the sender. In the object mock, attributedT...

CVE-2026-58593

NodeBB is affected by CVE-2026-58593 where inbound ActivityPub objects are not correctly bound to the authenticated remote actor. The middleware verifies the HTTP-signature actor and origin of object.id but does not validate that attributedTo corresponds to the sender, treating attributedTo as a ...

PT-2026-54922

Name of the Vulnerable Software and Affected Versions NodeBB affected versions not specified Description NodeBB fails to bind the claimed author of an inbound ActivityPub object to the authenticated remote actor. While the inbound middleware verifies the HTTP-signature actor and the origin of the...

BIT-GHOST-2026-53950 @tryghost/activitypub: XSS in Ghost's ActivityPub client

@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...

CVE-2026-46348

Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, the list of disallowed IP address ranges was lacking an IP address range that can be used to reach local IP addresses. An attacker can use an IP address in the affected range to make...

CVE-2026-48028

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...

CVE-2026-46349

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 attackers to...

CVE-2026-53950

@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...

CVE-2026-53950 @tryghost/activitypub: XSS in Ghost's ActivityPub client

@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...