Live › vulnerability › CVE-2026-112112
Go to dashboardBIRD, the CZ.NIC BGP routing daemon, fails to reject IPv6 FlowSpec destination prefixes with a nonzero offset when validation is enabled on a flow6 channel. An established BGP peer can get rules matching address space it is not authorized for, which may then propagate to downstream peers and filter or redirect traffic.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Only networks running BIRD as a BGP speaker that accept IPv6 FlowSpec from peers on a flow6 channel with validation enabled. Exposure depends on a valid unicast route from that peer and on export policy that forwards the rules downstream. Teams using BIRD only for IPv4 unicast, or without flow6 channels, can skip it.
No product ranges from the sources yet.
birdc show protocols all and check whether any BGP peer has a flow6 channel with FlowSpec import and validation enabled.bird --version (or birdc show status) and compare it against the fixed release named in the NVD record.Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
An IPv6 FlowSpec validation bypass in the CZ.NIC BIRD Internet Routing Daemon allows an established BGP peer to inject FlowSpec rules matching destinations outside the address space authorized by the unicast-route validation procedure. With validation enabled on the receiving flow6 channel, BIRD fails to reject a destination prefix component with a nonzero offset, contrary to RFC 8956 section 5. It validates a reconstructed prefix with zero-filled skipped bits, although the original FlowSpec component can match a broader set of IPv6 addresses. Given a suitable unicast route from the peer, the rule can pass validation and, where export policy permits, be propagated to downstream peers. Downstream enforcement may cause unauthorized traffic filtering or redirection.
This page as .md · .json · in your agent: get_signal("CVE-2026-112112")
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