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...

BIT-MASTODON-2026-46349 Mastodon: LD-Signature Bypass via JSON-LD Named-Graph Restructuring

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...

PYSEC-2026-284 Hyperledger Aries Cloud Agent Python result of presentation verification not checked for LDP-VC

Impact When verifying W3C Format Verifiable Credentials using JSON-LD with Linked Data Proofs LDP-VCs, the result of verifying the presentation document.proof was not factored into the final verified value true/false on the presentation record. Below is an example result from verifying a JSON-LD...

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-2026-50128 Mastodon: Spoofing of attribution domains

Mastodon is a free, open-source social network server based on ActivityPub. From 4.3.0 until 4.5.11 and 4.4.18, Mastodon has a feature to let websites credit authors of their articles. To prevent false attribution claims, Mastodon uses the attributionDomains JSON-LD term, however, an error in how...

CVE-2026-50128

Mastodon vulnerability CVE-2026-50128 affects versions 4.3.0 through 4.5.11 and 4.4.18, where an error in the attributionDomains JSON-LD handling allows an attacker to arbitrarily modify the attributionDomains value on a legitimately signed Update and bypass signature verification. This can under...

CVE-2026-50128

Mastodon is a free, open-source social network server based on ActivityPub. From 4.3.0 until 4.5.11 and 4.4.18, Mastodon has a feature to let websites credit authors of their articles. To prevent false attribution claims, Mastodon uses the attributionDomains JSON-LD term, however, an error in how...

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-2026-48028

Mastodon (open-source social network server) versions prior to 4.5.10, 4.4.17, and 4.3.23 are affected. The vulnerability arises from how incoming activities signed with Linked-Data Signatures are normalized, failing to adequately protect against a class of spoofing that lets an attacker remove J...

CVE-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-2026-48028 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-2026-46349 Mastodon: LD-Signature Bypass via JSON-LD Named-Graph Restructuring

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-2026-46349

CVE-2026-46349 affects Mastodon before versions 4.5.10, 4.4.17, and 4.3.23. The issue arises from Mastodon’s normalization of incoming activities signed with Linked-Data Signatures, which does not sufficiently prevent a class of spoofing. An attacker could re-arrange a valid signed JSON-LD activi...

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-2026-46349 Mastodon: LD-Signature Bypass via JSON-LD Named-Graph Restructuring

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...

PT-2026-52078

Name of the Vulnerable Software and Affected Versions Mastodon versions prior to 4.5.10 Mastodon versions prior to 4.4.17 Mastodon versions prior to 4.3.23 Description Mastodon is a free, open-source social network server based on ActivityPub. The normalization of incoming activities signed with...

PT-2026-52080

Name of the Vulnerable Software and Affected Versions Mastodon versions prior to 4.5.10 Mastodon versions prior to 4.4.17 Mastodon versions prior to 4.3.23 Description Mastodon is a free, open-source social network server based on ActivityPub. The normalization of incoming activities signed with...

CVE-2026-42462 Fedify has an LD-Signature Bypass via JSON-LD Named-Graph Restructuring

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...

CVE-2026-42462

CVE-2026-42462 describes an LD-Signature bypass in Fedify caused by JSON-LD named-graph restructuring. The issue allows an attacker to reorganize a signed JSON-LD payload (via features like @graph, @reverse, @included) in a way that changes how the signed ActivityPub activity is interpreted witho...