CVE-2026-41643

GoBGP: Remote Denial of Service (Panic) in UpdatePathAttrs4ByteAs via Malformed BGP UPDATE

GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. Prior to version 4.3.0, a remote Denial of Service (DoS) vulnerability exists in GoBGP where a malformed BGP UPDATE message can trigger a runtime error: index out of range panic. This occurs during the processing of 4-byte AS attributes when the message structure causes an internal slice index shift that is not properly handled. This issue has been patched in version 4.3.0.

Affected

osrg · gobgp

CVSS v3.1 GITHUB

7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.60% chance of exploitation in the next 30 days, 48th percentile

Published

2026-05-07

Proof-of-concept exploits (1)

• advisories/GHSA-8rxh-r2p6-7f2q

Security advisories

• osrg/gobgp/security/advisories/GHSA-8rxh-r2p6-7f2q
• osrg/gobgp/releases/tag/v4.3.0

References

• CVE Record
• NVD entry