Vulnerability · Published Oct 18, 2026 · Assigned by mitre
CVE-2026-112112
Low 2.3
In plain English
A low-severity security flaw in BIRD from nic. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | bird2 | no fix listed | DEBIAN-CVE-2026-112112 |
| Debian:13 | bird2 | no fix listed | DEBIAN-CVE-2026-112112 |
| Debian:14 | bird2 | no fix listed | DEBIAN-CVE-2026-112112 |
| Debian:13 | bird3 | no fix listed | DEBIAN-CVE-2026-112112 |
| Debian:14 | bird3 | no fix listed | DEBIAN-CVE-2026-112112 |
| Ubuntu:22.04:LTS | bird2 | no fix listed | UBUNTU-CVE-2026-112112 |
| Ubuntu:24.04:LTS | bird2 | no fix listed | UBUNTU-CVE-2026-112112 |
| Ubuntu:26.04:LTS | bird2 | no fix listed | UBUNTU-CVE-2026-112112 |
| Ubuntu:26.10 | bird2 | no fix listed | UBUNTU-CVE-2026-112112 |
| Ubuntu:26.04:LTS | bird3 | no fix listed | UBUNTU-CVE-2026-112112 |
| Ubuntu:26.10 | bird3 | no fix listed | UBUNTU-CVE-2026-112112 |
Affected products (as reported)
Weakness: CWE-1284 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N