CVE-2026-41642: GoBGP: Remote Denial of Service (Panic) via Malformed Well-known Path Attribute

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-476

Description

GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. In version 4.3.0, a remote Denial of Service (DoS) vulnerability exists in GoBGP due to a nil pointer dereference. When a malformed BGP UPDATE message contains an unrecognized Path Attribute marked as "Well-known," the daemon fails to interrupt the message handling flow. This results in an illegal memory access and a full process crash (panic). This issue has been patched in version 4.4.0.

Affected products

osrg GoBGP: 4.3.0

References

https://github.com/osrg/gobgp/releases/tag/v4.4.0
https://github.com/osrg/gobgp/security/advisories/GHSA-7235-89m6-f4px
https://github.com/osrg/gobgp/security/advisories/GHSA-7235-89m6-f4px

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