{"schemaVersion":3,"id":"CVE-2026-112112","aliases":["DEBIAN-CVE-2026-112112"],"status":"published","duplicateOf":null,"title":null,"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.","dates":{"published":"2026-10-18T23:01:05.633Z","modified":"2026-10-18T23:01:05.633Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":2.3,"severity":"low","version":"4.0","versionLabel":"v4.0","source":"CVE.org","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","computed":false,"selection":"backend-summary"},"metrics":[{"version":"4.0","versionLabel":"v4.0","source":"CVE.org","score":2.3,"severity":"low","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","exploitability":null,"impact":null,"computed":false},{"version":"4.0","versionLabel":"v4.0","source":"NVD","score":2.3,"severity":"low","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","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00307,"percentile":0.22127,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[{"date":"2026-10-19T00:00:00.000Z","score":0.00307,"percentile":0.22127}],"last30":[{"date":"2026-10-19T00:00:00.000Z","score":0.00307,"percentile":0.22127}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-1284","name":"Improper Validation of Specified Quantity in Input","description":"The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.","type":"weakness","status":"Incomplete","abstraction":"Base","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/1284.html"}],"affected":[{"vendor":"debian","product":"bird2","name":"bird2","label":"bird2","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/bird2","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"debian","product":"bird3","name":"bird3","label":"bird3","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/bird3","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"nic","product":"bird","name":"BIRD","label":"bird","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 2.0.9, ≤ 2.20.0","noFixRecorded":false,"fixedIn":null},{"text":"≥ 3.0.0, ≤ 3.4.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 2.0.9, ≤ 2.20.0 | ≥ 3.0.0, ≤ 3.4.0","eol":null,"hubHref":"/vendor/nic/bird"}],"affectedCount":3,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://gitlab.nic.cz/labs/bird/-/commit/7cf75587b6f38b87849fe192bf5dfd124b7702bc","label":"gitlab.nic.cz/labs/bird/-/commit/7cf75587b6f38b87849fe192bf5dfd124b7702bc","hostname":"gitlab.nic.cz","tags":["Patch"]},{"url":"https://www.rfc-editor.org/rfc/rfc8956.html#section-5","label":"www.rfc-editor.org/rfc/rfc8956.html","hostname":"www.rfc-editor.org","tags":[]},{"url":"https://gitlab.nic.cz/labs/bird/-/blob/v2.20.0/nest/rt-table.c#L2686","label":"gitlab.nic.cz/labs/bird/-/blob/v2.20.0/nest/rt-table.c","hostname":"gitlab.nic.cz","tags":[]},{"url":"https://gitlab.nic.cz/labs/bird/-/blob/v3.4.0/nest/rt-table.c#L4518","label":"gitlab.nic.cz/labs/bird/-/blob/v3.4.0/nest/rt-table.c","hostname":"gitlab.nic.cz","tags":[]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-112112","label":"security-tracker.debian.org/tracker/CVE-2026-112112","hostname":"security-tracker.debian.org","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-10-18T23:01:05.633Z","label":"Published","detail":"Vulnerability first disclosed.","source":null}],"risk":{"score":9,"level":"minimal","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-19T15:08:07.946Z","stale":false,"partial":false}}