CVE-2026-112112 Security feature bypass in BIRD
A BGP peer can bypass IPv6 FlowSpec validation to inject unauthorized traffic filtering or redirection rules, affecting network operators using BIRD.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-112112?
CVE-2026-112112 is a low-severity vulnerability in nic BIRD, published on 18 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-1284
Which versions are affected by CVE-2026-112112?
How do I fix CVE-2026-112112?
No fix has been published for CVE-2026-112112 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-112112 being exploited?
There is no known exploitation of CVE-2026-112112 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-112112, GHSA-6jp9-p482-x6c9, UBUNTU-CVE-2026-112112.