CVE-2026-49838CWE-129

CVE-2026-49838

Medium · published September 11, 2026

CVSS v3.1
5.9
EPSS
0%
Percentile
34.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
5.9 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00412 · 34.4th percentile
Weakness
CWE-129 · Improper Validation of Array Index
Published
2026-09-11T02:16Z
References (2)
EPSS history
Timeline
  • 12 SEP 03:21Z
    EPSS moved — → 0%
    epss
  • 10 SEP 21:57Z
    GoBGP confederation validation panics on empty AS_PATH attribute
    cvelistv5