Bug 2531686 (CVE-2026-49838)

Summary:	CVE-2026-49838 github.com/osrg/gobgp: GoBGP: Denial of Service via malformed BGP UPDATE message
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, kshier, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, sghai, sidsharm, stcannon, suppawar, teagle, vlaad, yguenane
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in GoBGP, an open-source Border Gateway Protocol (BGP) implementation. A configured confederation eBGP peer can send a specially crafted BGP UPDATE message with a zero-length AS_PATH attribute. This malformed message is improperly handled during validation, leading to an unchecked memory access that causes the GoBGP process to crash. This vulnerability results in a denial of service for the affected system.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-10 22:01:41 UTC

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.