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...

Crawl4AI: SSRF filter bypass in Docker server via IPv6 transition forms (NAT64 / 6to4 / unspecified / v4-mapped)

Summary The Docker API server's SSRF protection validatewebhookurl / validateurldestination in deploy/docker/utils.py used an explicit IPv4/IPv6 CIDR blocklist that missed several address families. An attacker could reach internal services and cloud metadata endpoints e.g. 169.254.169.254 despite...

PT-2026-50129

Summary When an application using Pydantic AI opts a URL into force download='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...

GHSA-38CX-CQ6F-5755 Symfony: IpUtils::PRIVATE_SUBNETS Omits IPv6 Transition Forms (6to4, NAT64, Teredo, IPv4-compatible): SSRF Bypass in NoPrivateNetworkHttpClient

Description Symfony\Component\HttpClient\NoPrivateNetworkHttpClient is documented as a decorator that blocks requests to private networks by default. The list of blocked subnets Symfony\Component\HttpFoundation\IpUtils::PRIVATESUBNETS on 6.4+, a private constant in NoPrivateNetworkHttpClient on 5...