BIT-MASTODON-2026-72916 Mastodon: SSRF Protection Bypass via IPv4-compatible IPv6 Addresses

Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.4.21, 4.5.14, 4.6.4, and 4.7.0, PrivateAddressCheck.privateaddress? in app/lib/privateaddresscheck.rb normalized IPv4-mapped IPv6 addresses but did not recognize IPv4-compatible IPv6 addresses with...

CVE-2026-72916

Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.4.21, 4.5.14, 4.6.4, and 4.7.0-beta.1, PrivateAddressCheck.privateaddress? in app/lib/privateaddresscheck.rb normalized IPv4-mapped IPv6 addresses but did not recognize IPv4-compatible IPv6 addresses with...

CVE-2026-72916 Mastodon: SSRF Protection Bypass via IPv4-compatible IPv6 Addresses

Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.4.21, 4.5.14, 4.6.4, and 4.7.0-beta.1, PrivateAddressCheck.privateaddress? in app/lib/privateaddresscheck.rb normalized IPv4-mapped IPv6 addresses but did not recognize IPv4-compatible IPv6 addresses with...

EUVD-2026-55839

Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.4.21, 4.5.14, 4.6.4, and 4.7.0-beta.1, PrivateAddressCheck.privateaddress? in app/lib/privateaddresscheck.rb normalized IPv4-mapped IPv6 addresses but did not recognize IPv4-compatible IPv6 addresses with...

PYSEC-2026-2981 pydantic-ai: SSRF blocklist bypass via IPv4-compatible, SIIT/IVI, and local NAT64 IPv6 addresses (incomplete fix of CVE-2026-46678)

Summary When an application using Pydantic AI opts a URL into forcedownload='allow-local' which disables the default block on private/internal IPs and runs on a network that routes the affected IPv6 transition forms NAT64- or ISATAP-configured networks, the cloud-metadata blocklist could be...

CVE-2026-48782 pydantic-ai: SSRF blocklist bypass via IPv4-compatible, SIIT/IVI, and local NAT64 IPv6 addresses (incomplete fix of CVE-2026-46678)

Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. In versions 1.56.0 through 1.101.0, 2.0.0b1, and 2.0.0b2, the cloud-metadata blocklist could be bypassed by encoding the metadata IP in an IPv6 transition form that the previous fix, CVE-2026-46678...