In FRRouting (FRR) 8.3 through 10.5.1, bgp_notify_decapsulate_hard_reset() in bgpd/bgp_packet.c does not validate the length of the data field of a received BGP NOTIFICATION Cease/Hard Reset message (RFC 8538). When the data field is exactly one byte long, the function reads one byte past the end of a heap buffer and the 16-bit length of the encapsulated data underflows to 65535, causing a 65535-byte out-of-bounds heap read followed by an assertion failure. A remote BGP peer that has established a session and negotiated the Graceful Restart capability with the Notification (N) bit can send such a message to crash the bgpd daemon, terminating all BGP sessions (denial of service). This is fixed in 10.0.5, 10.1.5, 10.2.6, 10.3.4, 10.4.3, 10.5.2 and 10.6.0.

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Fixes

Solution

Upgrade to a fixed version of FRRouting


Workaround

Graceful Restart Capability needs to be enabled. Disable the Capability with "no bgp graceful-restart notification" or "bgp graceful-restart-disable"

History

Fri, 13 Nov 2026 19:15:00 +0000

Type Values Removed Values Added
Description In FRRouting (FRR) 8.3 through 10.5.1, bgp_notify_decapsulate_hard_reset() in bgpd/bgp_packet.c does not validate the length of the data field of a received BGP NOTIFICATION Cease/Hard Reset message (RFC 8538). When the data field is exactly one byte long, the function reads one byte past the end of a heap buffer and the 16-bit length of the encapsulated data underflows to 65535, causing a 65535-byte out-of-bounds heap read followed by an assertion failure. A remote BGP peer that has established a session and negotiated the Graceful Restart capability with the Notification (N) bit can send such a message to crash the bgpd daemon, terminating all BGP sessions (denial of service). This is fixed in 10.0.5, 10.1.5, 10.2.6, 10.3.4, 10.4.3, 10.5.2 and 10.6.0.
Title bgpd: out-of-bounds heap read and crash on NOTIFICATION Cease/Hard Reset with one data byte
Weaknesses CWE-125
CWE-191
References
Metrics cvssV4_0

{'score': 6, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: NetDEF

Published:

Updated: 2026-11-13T19:06:40.219Z

Reserved: 2026-11-13T19:02:49.870Z

Link: CVE-2026-129217

cve-icon Vulnrichment

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cve-icon NVD

Status : Received

Published: 2026-11-13T19:19:32.050

Modified: 2026-11-13T19:19:32.050

Link: CVE-2026-129217

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses