CVE-2026-49838: medium-severity vulnerability in osrg gobgp
GoBGP confederation validation panics on empty AS_PATH attribute
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.9epss 0.4%
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
osrg · gobgpRelated CVEs — osrg gobgp
In the same product, most dangerous first.
CVE-2026-41643HIGHGoBGP: Remote Denial of Service (Panic) in UpdatePathAttrs4ByteAs via Malformed BGP UPDATEEPSS 0.5%CVE-2026-41642HIGHGoBGP: Remote Denial of Service (Panic) via Malformed Well-known Path AttributeEPSS 0.5%CVE-2026-42285HIGHGoBGP: Panic in AdjRib.Update via malformed BGP Update message (Nil Pointer Dereference)EPSS 0.4%CVE-2026-49837MEDIUMGoBGP: BGP OPEN capability parser may read capability values outside declared CapLen boundariesEPSS 0.3%