What’s Vulnerable › Vulnerabilities

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

• Severity: low (CVSS 3.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-30 · updated 2026-06-17
• Weakness: CWE-189

Description

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.

Affected products

• osrg GoBGP: before 4.4.0 — fixed in 4.4.0

How to fix

Upgrade to a fixed version: osrg GoBGP 4.4.0. Check the vendor advisory for mitigations.

References

• https://github.com/osrg/gobgp/
• https://github.com/osrg/gobgp/commit/67c059413470df64bc20801c46f64058e88f800f
• https://github.com/osrg/gobgp/pull/3342
• https://vuldb.com/submit/780179
• https://vuldb.com/vuln/354155
• https://vuldb.com/vuln/354155/cti

Get alerted when CVE-2026-5123 or the next vulnerability affects your stack