What’s Vulnerable › Vulnerabilities

CVE-2026-41643: GoBGP: Remote Denial of Service (Panic) in UpdatePathAttrs4ByteAs via Malformed BGP UPDATE

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-05-07 · updated 2026-10-26
• Weakness: CWE-129

Description

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 products

• osrg GoBGP: before 4.3.0 — fixed in 4.3.0

How to fix

Upgrade to a fixed version: osrg GoBGP 4.3.0. Check the vendor advisory for mitigations.

References

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

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