Is there a public exploit for CVE-2026-129456?

No public exploit for CVE-2026-129456 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-129456?

CVE-2026-129456 scores CVSS 7.7 (v4.0), rated high.

What does CVE-2026-129456 affect?

CVE-2026-129456 affects FRRouting FRRouting.

7.7 High

In FRRouting, bgpd accepts a Tunnel Encapsulation attribute (type 23) whose outer TLV length does not match the length of the attribute:…

CVE-2026-129456

In FRRouting, bgpd accepts a Tunnel Encapsulation attribute (type 23) whose outer TLV length does not match the length of the attribute: the mismatch is only logged and the attribute is processed anyway. A BGP neighbor can send UPDATE messages carrying such an attribute that put the reference count of the attribute's interned sub-TLV chain out of balance, so that the chain is freed while routes stored by bgpd (Adj-RIB-In entries and RIB paths) still point to it. When those routes are later replaced, withdrawn or cleared, for example when the session goes down, bgpd reads the freed memory, decrements a reference count inside it and frees it a second time. In the reporter's build without AddressSanitizer this ended in an assertion failure in bgpd's memory accounting, aborting bgpd and dropping all BGP sessions on the router, and the neighbor can repeat it each time bgpd restarts. Because freed heap memory is written to and freed again, consequences beyond a crash cannot be ruled out. An established BGP session is required. bgpd processes attribute 23 from every neighbor, including eBGP neighbors, unless it is explicitly discarded, although RFC 9012 requires it to be filtered on eBGP…

Assessment

CVSS: 7.7 (v4.0)
Severity: High
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 14 November 2026
Last updated: 14 November 2026
Affected: FRRouting · FRRouting
Assigner: NetDEF

CVSS vectorCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/AU:N/R:A

At the source

EUVD (ENISA)

References

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