CVE-2026-119776: frr: ospf6d fails to enforce all OSPFv3 packets use IPv6 link-local addresses
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.4%
EPSS score, percentile 34.2 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 6.1 Medium
CVSS v4.0 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
- Which versions are affected?
Affected
- unspecified
Unaffected from eaccfcdb35bc
Source: CISA KEV 2026.11.10, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
Description
frr: ospf6d fails to enforce all OSPFv3 packets use IPv6 link-local addresses
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. Required configuration: The OSPFv3 for IPv6 routing protocol must be running (ospf6d process) and in use (enabled globally with "router ospf6" and on specific interfaces with "ipv6 ospf6 area".) Workaround: either: * configure OSPFv3 authentication trailers ("ipv6 ospf6 authentication") * or ensure through firewall configuration that only packets with link-local or multicast destination addresses are accepted on input for IPv6 protocol 89 (OSPF). Note that checking the source address is insufficient, as some routers may (unexpectedly) forward packets with global-scoped IPv6 destination addresses even if they have link-local source addresses.
Source: CVE List, as of . About the data.
What to do
Advisories and patches
Workaround (from the CVE record)
Either: * configure OSPFv3 authentication trailers ("ipv6 ospf6 authentication") * or ensure through firewall configuration that only packets with link-local or multicast destination addresses are accepted on input for IPv6 protocol 89 (OSPF). Note that checking the source address is insufficient, as some routers may (unexpectedly) forward packets with global-scoped IPv6 destination addresses even if they have link-local source addresses.
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
Versions by product, as listed in the CVE record (1 product)
| Status | Versions |
|---|---|
| Affected | unspecified |
| Unaffected | from eaccfcdb35bc |
Versions not listed are: affected.
Versions the record lists as unaffected: eaccfcdb35bce8d94621b06633417ba3fa657f34.
Source: CVE List, as of . About the data.
Weakness
CWE-304
- CWE-304: Missing critical step in authentication: protocol interactions should be limited to IPv6 link-local scope
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |