CVE-2026-37462: GoBGP Integer Underflow Vulnerability

HIGH
Advisory Identifier: GHSA-pw7p-7fqv-hpj8
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CVSS 7.3
CWE-190
Published
Advisory Summary

CVE-2026-37462 is a HIGH (CVSS 7.3) integer underflow vulnerability (CWE-190: Integer Overflow or Wraparound) affecting GoBGP libraries in the Go ecosystem. The issue involves integer underflow in the bgpupdate.decodefrombytes function. Remediation is available by upgrading affected packages to version 4.4.0.

CVE-2026-37462 at a Glance

CVE Identifier CVE-2026-37462
GHSA Identifier GHSA-pw7p-7fqv-hpj8
Severity HIGH
CVSS v3.1 Base Score 7.3
CWE Classification CWE-190: Integer Overflow or Wraparound
Affected Product GoBGP
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability Low (A:L)

How to Fix CVE-2026-37462

To remediate this vulnerability, upgrade all affected GoBGP dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/osrg/gobgp/v4 fixed: 4.4.0 
Upgrade github.com/osrg/gobgp/v4 to 4.4.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/osrg/gobgp/v4

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-37462, inspect your project dependencies for GoBGP:

inspect dependencies for github.com/osrg/gobgp/v4

Analyze the terminal output to locate any version of GoBGP in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.4.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-190: Integer Overflow or Wraparound, where the product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. this occurs when an integer value is incremented to a value that is too large to store in the associated representation. when this occurs, the value may become a very small or negative number. In GoBGP, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

An integer underflow in the BGPUpdate.DecodeFromBytes function (/bgp/bgp.go) of gobgp v4.3.0 allows attackers to cause a Denial of Service (DoS) via supplying a crafted BGP UPDATE message.

CVE-2026-37462 Affected GoBGP Versions

1 component(s)
Fixed Versions:
4.4.0
Product / Package Ecosystem Affected Versions Fixed Version
github.com/osrg/gobgp/v4
golang/github.com/osrg/gobgp/v4
Go
< 4.4.0
4.4.0

References

NVD — CVE-2026-37462 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-37462
Security Fix Commit FIX COMMIT
https://github.com/osrg/gobgp/commit/9ce8936672ebc07df524da77fa4c6ae26d92be6d
GoBGP Source Repository REPOSITORY
https://github.com/osrg/gobgp
GoBGP Source Repository REPOSITORY
https://github.com/osrg/gobgp/blob/v4.3.0/pkg/packet/bgp/bgp.go

Frequently Asked Questions

What is CVE-2026-37462?
CVE-2026-37462 is a security vulnerability in GoBGP involving Integer underflow in the BGPUpdate.DecodeFromBytes function under CWE-190: Integer Overflow or Wraparound.
Which GoBGP versions are affected?
Affected versions include releases prior to 4.4.0 across affected packages: github.com/osrg/gobgp/v4.
What version fixes CVE-2026-37462?
Upgrading to 4.4.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/osrg/gobgp/v4 affected?
Yes, github.com/osrg/gobgp/v4 is affected in releases prior to 4.4.0. Upgrade your dependency to 4.4.0 or later.
What is the CVSS score of CVE-2026-37462?
CVE-2026-37462 has a CVSS v3.1 base score of 7.3 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
What CWE is associated with CVE-2026-37462?
CVE-2026-37462 is classified under CWE-190: Integer Overflow or Wraparound (The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.).
How can I check Go dependencies for CVE-2026-37462?
Run the dependency tree command: 'inspect dependencies for github.com/osrg/gobgp/v4'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-pw7p-7fqv-hpj8",
  "modified" : "2026-07-13T17:27:40Z",
  "published" : "2026-06-03T18:33:09Z",
  "aliases" : [ "CVE-2026-37462" ],
  "summary" : "GoBGP: Integer underflow in the BGPUpdate.DecodeFromBytes function",
  "details" : "An integer underflow in the BGPUpdate.DecodeFromBytes function (/bgp/bgp.go) of gobgp v4.3.0 allows attackers to cause a Denial of Service (DoS) via supplying a crafted BGP UPDATE message.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/osrg/gobgp/v4"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.4.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-37462"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/osrg/gobgp/commit/9ce8936672ebc07df524da77fa4c6ae26d92be6d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/osrg/gobgp"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/osrg/gobgp/blob/v4.3.0/pkg/packet/bgp/bgp.go"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-190" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-13T17:27:40Z",
    "nvd_published_at" : "2026-06-03T16:16:29Z"
  }
}