CVE-2026-119776 · Runtime
NO FIX YET
FRRouting's OSPFv3 implementation for IPv6 does not check that packets come from a link-local source and go to a link-local or protocol multicast destination. An attacker on a distant IPv6 host can establish OSPFv3 adjacencies with the router, and authentication trailers (RFC 7166) limit full exploitation but can still be used to waste CPU.
first public Nov 4, 2026 · 1 source
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Routers and Linux hosts running FRRouting with OSPFv3 (IPv6) enabled are exposed. The description says authentication trailers per RFC 7166 prevent full exploitation, so teams using them face less risk. Teams not running OSPFv3 can skip it. The linked PR #23935 is stated as insufficient, so the source does not confirm a fixed release.
Not affected if no-ospfv3, ospf-authentication-trailers
Who cares frrouting, ipv6, ospfv3, routers
vtysh -c 'show version'; all prior released versions are listed as affected in the description.vtysh -c 'show ipv6 ospf6 interface'.Unknown from the sources.
In all prior released versions of FRRouting, the OSPFv3 (for IPv6) implementation does not check that OSPFv3 packets have a link-local source address and either a link-local destination or one of the protocol multicast destination groups. This may enable malicious actors to establish OSPFv3 adjacencies from unexpectedly, distant IPv6 hosts. Proper usage of OSPFv3 authentication trailers (RFC 7166, as is best practice) prevents full exploitation of this issue, though may allow a malicious actor to waste CPU on authentication checks.
Note the linked PR #23935 is not sufficient to fix the issue as it only verifies the source address. It is the destination address that must be checked.
This page as .md · .json · in your agent: get_signal("CVE-2026-119776") · CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:H/VA:H/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:Y/R:X/V:X/RE:X/U:X
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