CVE-2026-129217
bgpd: out-of-bounds heap read and crash on NOTIFICATION Cease/Hard Reset with one data byte
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.
INFO
Published Date :
Nov. 13, 2026, 7:19 p.m.
Last Modified :
Nov. 13, 2026, 7:19 p.m.
Remotely Exploit :
Yes !
Source :
57a55968-44ac-464c-a794-6ba3baad09c4
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | 57a55968-44ac-464c-a794-6ba3baad09c4 | ||||
| CVSS 4.0 | MEDIUM | 57a55968-44ac-464c-a794-6ba3baad09c4 |
Solution
- Update FRRouting to a fixed version.
- Apply available patches for FRR.
- Restart the bgpd daemon.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-129217.
| URL | Resource |
|---|---|
| https://github.com/FRRouting/frr/issues/20793 | |
| https://github.com/FRRouting/frr/pull/20796 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-129217 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-129217
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-129217 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-129217 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 57a55968-44ac-464c-a794-6ba3baad09c4
Nov. 13, 2026
Action Type Old Value New Value 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. Added CVSS V4.0 AV:N/AC:H/AT:P/PR:H/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:X/R:X/V:X/RE:X/U:X Added CWE CWE-125 Added CWE CWE-191 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/129xxx/CVE-2026-129217.json">CVE-2026-129217</a> Added Reference https://github.com/FRRouting/frr/issues/20793 Added Reference https://github.com/FRRouting/frr/pull/20796