Medium severity · published Sep 10, 2026
CVE-2026-49838
GoBGP confederation validation panics on empty AS_PATH attribute
5.9
CVSS
0.4%
EPSS
No
On KEV
Description
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 vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 35% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GO
gobgp · osrg
< 4.7.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-49838
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-49838
github.com
https://github.com/osrg/gobgp/commit/4a319a6c25630fb3cdbda3e9ccfe56e702bdaaa0
github.com
https://github.com/osrg/gobgp/security/advisories/GHSA-frrj-87jh-2772
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