{"id":"CVE-2026-112112","aliases":["DEBIAN-CVE-2026-112112","EUVD-2026-104014","GHSA-6jp9-p482-x6c9","UBUNTU-CVE-2026-112112"],"status":"published","title":"An IPv6 FlowSpec validation bypass in the CZ.NIC BIRD Internet Routing Daemon allows an...","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.","severity":{"version":"4.0","score":2.3,"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","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00308,"percentile":0.23837,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-1284"],"published":"2026-10-18T23:01:05Z","modified":"2026-10-28T20:17:32Z","affected":[{"source":"osv","ecosystem":"Debian:12","package":"bird2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.12-7","2.14-1","2.15-1","2.15.1-1","2.15.1-1.1","2.16-1","2.16.1-1","2.17-1","2.17.1-1","2.17.2-1","2.17.3-1","2.17.3-2","2.18-1","2.18.1-1","2.19.0-1","2.19.1-1","2.19.2-1","2.20.0-1"]},{"source":"osv","ecosystem":"Debian:13","package":"bird2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.17.1-1","2.17.1-1+deb13u1","2.17.1-1+deb13u2","2.17.2-1","2.17.3-1","2.17.3-2","2.17.5-0+deb13u1","2.18-1","2.18.1-1","2.19.0-1","2.19.1-1","2.19.2-1","2.20.0-1"]},{"source":"osv","ecosystem":"Debian:14","package":"bird2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.17.1-1","2.17.2-1","2.17.3-1","2.17.3-2","2.18-1","2.18.1-1","2.19.0-1","2.19.1-1","2.19.2-1","2.20.0-1"]},{"source":"osv","ecosystem":"Debian:13","package":"bird3","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.0-1","3.1.4-1","3.1.5-1","3.1.5-2","3.1.7-0+deb13u1","3.2.0-1","3.2.1-1","3.3.0-1","3.3.0-1~bpo13+1","3.3.1-1","3.3.2-1","3.3.2-1~bpo13+1","3.4.0-1"]},{"source":"osv","ecosystem":"Debian:14","package":"bird3","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.0-1","3.1.4-1","3.1.5-1","3.1.5-2","3.2.0-1","3.2.1-1","3.3.0-1","3.3.0-1~bpo13+1","3.3.1-1","3.3.2-1","3.3.2-1~bpo13+1","3.4.0-1"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"bird2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.5-1","2.0.7-2"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"bird2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.7-4.1","2.0.8-2"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"bird2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.12-7","2.14-1","2.14-1build1","2.14-1build2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"bird2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.18-1","2.18.1-1","2.19.0-1","2.19.1-1","2.19.2-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"bird3","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.2.0-1","3.2.1-1","3.3.0-1","3.3.1-1","3.3.2-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"bird2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.17.1-1","2.17.2-1","2.17.3-1","2.17.3-2","2.18-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"bird3","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.0-1","3.1.4-1","3.1.5-1","3.1.5-2","3.2.0-1"]}],"products":[{"vendor":"nic","product":"bird"}],"references":[{"url":"https://gitlab.nic.cz/labs/bird/-/commit/7cf75587b6f38b87849fe192bf5dfd124b7702bc","tags":["patch","fix"]},{"url":"https://www.rfc-editor.org/rfc/rfc8956.html#section-5","tags":["web"]},{"url":"https://gitlab.nic.cz/labs/bird/-/blob/v2.20.0/nest/rt-table.c#L2686","tags":["web"]},{"url":"https://gitlab.nic.cz/labs/bird/-/blob/v3.4.0/nest/rt-table.c#L4518","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-112112","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-6jp9-p482-x6c9"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/112xxx/CVE-2026-112112.json","tags":["advisory"]},{"url":"https://gitlab.nic.cz/labs/bird","tags":["package"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-112112","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-112112","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-112112","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-112112","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.","status":"published","published":"2026-10-18T23:01:05.633Z","modified":"2026-10-19T18:41:47.949Z","cvss":[{"version":"4.0","score":2.3,"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","level":"low","assessor":"cna"}],"cwes":["CWE-1284"],"updated_at":"2026-11-02T13:44:40.64332Z"}],"euvd":[{"id":"EUVD-2026-104014","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.","status":"published","published":"2026-10-18T23:01:05Z","modified":"2026-10-19T18:41:47Z","cvss":[{"version":"4.0","score":2.3,"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","level":"low"}],"updated_at":"2026-11-02T16:59:49.097498Z"}],"ghsa":[{"id":"GHSA-6jp9-p482-x6c9","title":"An IPv6 FlowSpec validation bypass in the CZ.NIC BIRD Internet Routing Daemon allows an...","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.","status":"published","published":"2026-10-19T00:30:24Z","modified":"2026-10-19T00:30:31Z","cvss":[{"version":"4.0","score":2.3,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"low"}],"cwes":["CWE-1284"],"updated_at":"2026-11-02T15:13:56.45986Z"}],"nvd":[{"id":"CVE-2026-112112","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.","status":"published","published":"2026-10-18T23:16:56.767Z","modified":"2026-10-19T21:14:14.15Z","cvss":[{"version":"4.0","score":2.3,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"low","assessor":"secondary"}],"cwes":["CWE-1284"],"updated_at":"2026-11-02T14:13:00.483792Z"}],"osv":[{"id":"CVE-2026-112112","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.","status":"published","published":"2026-10-18T23:01:05.633Z","modified":"2026-10-28T10:46:11.089688844Z","cvss":[{"version":"4.0","score":2.3,"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","level":"low"}],"cwes":["CWE-1284"],"updated_at":"2026-11-02T15:44:55.938017Z"},{"id":"DEBIAN-CVE-2026-112112","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.","status":"published","published":"2026-10-18T23:16:56.767Z","modified":"2026-10-23T18:05:33.649384129Z","cvss":[{"version":"4.0","score":2.3,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"low"}],"updated_at":"2026-11-02T15:45:49.824149Z"},{"id":"UBUNTU-CVE-2026-112112","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.","status":"published","published":"2026-10-18T23:16:00Z","modified":"2026-10-28T20:17:32.255619093Z","cvss":[{"version":"4.0","score":2.3,"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","level":"low"}],"updated_at":"2026-11-02T16:55:59.591851Z"}]}}