CVE-2026-55103

Discourse ActivityPub adds ActivityPub support to Discourse. Prior to commit 1c8518b0f2abdf31cbea3e0b242f74d8994a9ba5, inbound ActivityPub processing does not sufficiently verify that the actor authenticated by the signed request matches the Activity actor and owns the referenced federated post. ...

CVE-2026-55103

The Discourse ActivityPub component is vulnerable to insufficient verification of data authenticity and incorrect authorization. Specifically, inbound ActivityPub processing fails to verify that the authenticated actor matches the Activity actor and owns the referenced federated post. A remote at...

CVE-2026-55103 Discourse ActivityPub: Fix inbound actor validation and apply outbound request SSRF hardening

Discourse ActivityPub adds ActivityPub support to Discourse. Prior to commit 1c8518b0f2abdf31cbea3e0b242f74d8994a9ba5, inbound ActivityPub processing does not sufficiently verify that the actor authenticated by the signed request matches the Activity actor and owns the referenced federated post. ...

CVE-2026-33693

CVE-2026-33693: SSRF via 0.0.0.0 Bypass in activitypub-federation-rust v4isinvalid CVSS 6.5 Moderate Keywords: SSRF, 0.0.0.0, IP validation bypass, activitypub-federation, Lemmy, Rust, ActivityPub Table of Contents Overview Vulnerability Details Technical Analysis Attack Chain Impact Remediation...

cve-2026-47777

CVE-2026-47777 — Mastodon Featured Collections Authorization Bypass Overview I responsibly disclosed a High Severity Authorization Bypass vulnerability affecting Mastodon's experimental Featured Collections federation pipeline. CVE ID: CVE-2026-47777 Affected Component...

CVE-2026-104445

YesWiki before 4.6.7 contains an authentication bypass vulnerability in the ActivityPub inbox that fails to bind the verified HTTP signature signer to the activity actor. Unauthenticated attackers with any ActivityPub keypair can send signed Delete or Update activities referencing a mirrored...

CVE-2026-104463 YesWiki before 4.6.7 Unauthenticated SSRF via ActivityPub Inbox

YesWiki before 4.6.7 contains a server-side request forgery vulnerability that allows unauthenticated attackers to trigger server requests by sending signed Follow activities to the public forms actor inbox route. Attackers sign requests with their own keyId while supplying internal actor URLs in...

CVE-2026-104463 YesWiki before 4.6.7 Unauthenticated SSRF via ActivityPub Inbox

YesWiki before 4.6.7 contains a server-side request forgery vulnerability that allows unauthenticated attackers to trigger server requests by sending signed Follow activities to the public forms actor inbox route. Attackers sign requests with their own keyId while supplying internal actor URLs in...

CVE-2026-104463 YesWiki before 4.6.7 Unauthenticated SSRF via ActivityPub Inbox

YesWiki before 4.6.7 contains a server-side request forgery vulnerability that allows unauthenticated attackers to trigger server requests by sending signed Follow activities to the public forms actor inbox route. Attackers sign requests with their own keyId while supplying internal actor URLs in...

EUVD-2026-91456

YesWiki before 4.6.7 contains an authentication bypass vulnerability in the ActivityPub inbox that fails to bind the verified HTTP signature signer to the activity actor. Unauthenticated attackers with any ActivityPub keypair can send signed Delete or Update activities referencing a mirrored...

CVE-2026-104445 YesWiki before 4.6.7 Authentication Bypass via ActivityPub Inbox Actor Spoofing

YesWiki before 4.6.7 contains an authentication bypass vulnerability in the ActivityPub inbox that fails to bind the verified HTTP signature signer to the activity actor. Unauthenticated attackers with any ActivityPub keypair can send signed Delete or Update activities referencing a mirrored...

CVE-2026-104445 YesWiki before 4.6.7 Authentication Bypass via ActivityPub Inbox Actor Spoofing

YesWiki before 4.6.7 contains an authentication bypass vulnerability in the ActivityPub inbox that fails to bind the verified HTTP signature signer to the activity actor. Unauthenticated attackers with any ActivityPub keypair can send signed Delete or Update activities referencing a mirrored...

CVE-2026-104445 YesWiki before 4.6.7 Authentication Bypass via ActivityPub Inbox Actor Spoofing

YesWiki before 4.6.7 contains an authentication bypass vulnerability in the ActivityPub inbox that fails to bind the verified HTTP signature signer to the activity actor. Unauthenticated attackers with any ActivityPub keypair can send signed Delete or Update activities referencing a mirrored...

CVE-2026-104445

Versions of YesWiki prior to 4.6.7 are susceptible to an authentication bypass vulnerability within the ActivityPub inbox . The root cause is a failure to bind the verified HTTP signature signer to the activity actor. This allows unauthenticated attackers possessing any ActivityPub keypair to sen...

CVE-2026-104445: Authentication Bypass by Spoofing

YesWiki before 4.6.7 contains an authentication bypass vulnerability in the ActivityPub inbox that fails to bind the verified HTTP signature signer to the activity actor. Unauthenticated attackers with any ActivityPub keypair can send signed Delete or Update activities referencing a mirrored...

PT-2026-104255

YesWiki before 4.6.7 contains an authentication bypass vulnerability in the ActivityPub inbox that fails to bind the verified HTTP signature signer to the activity actor. Unauthenticated attackers with any ActivityPub keypair can send signed Delete or Update activities referencing a mirrored...

SUSE CVE-2026-90679

Forgejo 13.0.0 through 16.0.4, when "federation ENABLED = true" is set, has a spoofing issue that affects identity integrity but does not allow account takeover or content modification. It does not verify that the HTTP Signature on an incoming ActivityPub activity was produced by the key belongin...

CVE-2026-90679

A flaw was found in Forgejo when federation is enabled. This issue allows a remote attacker to spoof identities by submitting signature-valid ActivityPub activities attributed to any actor identity. The system fails to verify that the HTTP Signature on an incoming ActivityPub activity was produce...

CVE-2026-90679

Forgejo 13.0.0 through 16.0.4, when "federation ENABLED = true" is set, has a spoofing issue that affects identity integrity but does not allow account takeover or content modification. It does not verify that the HTTP Signature on an incoming ActivityPub activity was produced by the key belongin...

CVE-2026-90679

Forgejo 13.0.0 through 16.0.4, when "federation ENABLED = true" is set, has a spoofing issue that affects identity integrity but does not allow account takeover or content modification. It does not verify that the HTTP Signature on an incoming ActivityPub activity was produced by the key belongin...