CVE-2026-129217

bgpd: out-of-bounds heap read and crash on NOTIFICATION Cease/Hard Reset with one data byte

Published Nov 13, 2026 CVSS 4.0 · 6 Medium EPSS n/a KEV · Not listed
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.

Analysis

No analysis available yet

Remediation

Vendor Solution

Upgrade to a fixed version of FRRouting


Vendor Workaround

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

Tracking

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Advisories

No advisories available
History
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'}

Subscriptions

No data.

Weaknesses
  • CWE-125

    Out-of-bounds Read

  • CWE-191

    Integer Underflow (Wrap or Wraparound)

Sources

Status
PUBLISHED
Assigner
NetDEF
Published
Updated
Nov 13, 2026, 7:06 PM
Reserved
Nov 13, 2026, 7:02 PM
Status
Received
Published
Nov 13, 2026, 7:19 PM
Modified
Nov 13, 2026, 7:19 PM