CVE-2026-7736: Github.com/osrg/gobgp/v4 GoBGP Has An Integer Underflow Vulnerability

MODERATE
Advisory Identifier: GHSA-hj4w-qr9j-c4cf
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CVSS 7.3
CWE-191
Published
Advisory Summary

CVE-2026-7736 is a MODERATE (CVSS 7.3) gobgp has an integer underflow vulnerability (CWE-191: Integer Underflow (Wrap or Wraparound)) affecting Github.com/osrg/gobgp/v4 libraries in the Go ecosystem. The issue involves gobgp has an integer underflow issue. Remediation is available by upgrading affected packages to version 4.4.0.

CVE-2026-7736 at a Glance

CVE Identifier CVE-2026-7736
GHSA Identifier GHSA-hj4w-qr9j-c4cf
Severity MODERATE
CVSS v3.1 Base Score 7.3
CWE Classification CWE-191: Integer Underflow (Wrap or Wraparound)
Affected Product Github.com/osrg/gobgp/v4
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-2026-7736

To remediate this vulnerability, upgrade all affected Github.com/osrg/gobgp/v4 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-2026-7736, inspect your project dependencies for Github.com/osrg/gobgp/v4:

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

Analyze the terminal output to locate any version of Github.com/osrg/gobgp/v4 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-191: Integer Underflow (Wrap or Wraparound), where the product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result. In Github.com/osrg/gobgp/v4, 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

A vulnerability was determined in osrg GoBGP up to 4.3.0. Affected by this vulnerability is the function parseRibEntry of the file pkg/packet/mrt/mrt.go. Executing a manipulation can lead to integer underflow. It is possible to launch the attack remotely. Upgrading to version 4.4.0 addresses this issue. This patch is called 76d911046344a3923cbe573364197aa081944592. It is suggested to upgrade the affected component.

CVE-2026-7736 Affected Github.com/osrg/gobgp/v4 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-2026-7736 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-7736
Security Fix Commit FIX COMMIT
https://github.com/osrg/gobgp/commit/76d911046344a3923cbe573364197aa081944592
Github.com/osrg/gobgp/v4 Source Repository REPOSITORY
https://github.com/osrg/gobgp
Github.com/osrg/gobgp/v4 Release RELEASE
https://github.com/osrg/gobgp/releases/tag/v4.4.0
vuldb.com/submit/807604 WEB
https://vuldb.com/submit/807604
vuldb.com/vuln/360911 WEB
https://vuldb.com/vuln/360911
vuldb.com/vuln/360911/cti WEB
https://vuldb.com/vuln/360911/cti

Frequently Asked Questions

What is CVE-2026-7736?
CVE-2026-7736 is a security vulnerability in Github.com/osrg/gobgp/v4 involving GoBGP has an Integer Underflow Issue under CWE-191: Integer Underflow (Wrap or Wraparound).
Which Github.com/osrg/gobgp/v4 versions are affected?
Affected versions include releases prior to 4.4.0 across affected packages: github.com/osrg/gobgp/v4.
What version fixes CVE-2026-7736?
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-2026-7736?
CVE-2026-7736 has a CVSS v3.1 base score of 7.3 (MODERATE) 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-2026-7736?
CVE-2026-7736 is classified under CWE-191: Integer Underflow (Wrap or Wraparound) (The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.).
How can I check Go dependencies for CVE-2026-7736?
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-hj4w-qr9j-c4cf",
  "modified" : "2026-05-08T16:58:36Z",
  "published" : "2026-05-04T09:31:09Z",
  "aliases" : [ "CVE-2026-7736" ],
  "summary" : "GoBGP has an Integer Underflow Issue",
  "details" : "A vulnerability was determined in osrg GoBGP up to 4.3.0. Affected by this vulnerability is the function parseRibEntry of the file pkg/packet/mrt/mrt.go. Executing a manipulation can lead to integer underflow. It is possible to launch the attack remotely. Upgrading to version 4.4.0 addresses this issue. This patch is called 76d911046344a3923cbe573364197aa081944592. It is suggested to upgrade the affected component.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N"
  } ],
  "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-2026-7736"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/osrg/gobgp/commit/76d911046344a3923cbe573364197aa081944592"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/osrg/gobgp"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/osrg/gobgp/releases/tag/v4.4.0"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/submit/807604"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/vuln/360911"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/vuln/360911/cti"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-191" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-08T16:58:36Z",
    "nvd_published_at" : "2026-05-04T07:16:01Z"
  }
}