CVE-2026-49838
Medium
Description
GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. Prior to version 4.7.0, GoBGP accepts a zero-length AS_PATH during UPDATE decoding and later panics while validating that attribute for a confederation eBGP peer. The vulnerable path is in the BGP UPDATE validator: a malformed UPDATE that should be rejected as a malformed AS_PATH instead reaches an unchecked `p.Value[0]` access, allowing a configured confederation eBGP peer to trigger a denial of service. Version 4.7.0 patches the issue.
SeverityMedium
CVSS5.9
Exploit probability—
ProductGithub.com/osrg/gobgp/v4
PublishedSep 10, 2026
First seenSep 10, 2026
Weakness typeCWE-129CWE-129
How to fix
Update
- github.com/osrg/gobgp/v44.7.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| github.com/osrg/gobgp/v4Go | v < 4.7.0 | 4.7.0 |
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