CVE-2026-5123 MEDIUM

CVE-2026-5123: osrg GoBGP bgp.go DecodeFromBytes off-by-one

Vendor Osrg
Product GoBGP
Weakness CWE-193
Published March 30, 2026
Last update April 1, 2026

CVSS base score

6.3/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X

What the vulnerability does

01Description

A weakness has been identified in osrg GoBGP up to 4.3.0. This impacts the function DecodeFromBytes of the file pkg/packet/bgp/bgp.go. Executing a manipulation of the argument data[1] can lead to off-by-one. The attack may be launched remotely. Attacks of this nature are highly complex. The exploitability is said to be difficult. This patch is called 67c059413470df64bc20801c46f64058e88f800f. A patch should be applied to remediate this issue.

Key dates

02Disclosure timeline

March 30, 2026 CVE published
April 1, 2026 Record updated