CVE-2026-7737: osrg GoBGP out-of-bounds read in BMP Parser

CVE-2026-7737 · Severity: medium · CVSS 5.3 · Published 2026-05-04

GoBGP is an open-source implementation of the Border Gateway Protocol (BGP) used for routing internet traffic. A vulnerability in its BGP Monitoring Protocol (BMP) parser could allow a remote attacker to send specially crafted network packets that cause the service to read memory outside of intended boundaries. This can lead to service instability or crashes, potentially disrupting network routing operations.

Technologies: github.com/osrg/gobgp (Go), github.com/osrg/gobgp/v4 (Go), Osrg Gobgp. Vendors: Go, Osrg.

Quick answers

Is CVE-2026-7737 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-7737 being exploited in the wild.
How severe is CVE-2026-7737?
Medium severity, with a CVSS score of 5.3, published 4 May 2026.
Which products and versions are affected?
github.com/osrg/gobgp (Go) < 4.4.0, SEMVER:introduced=0,fixed=4.4.0; github.com/osrg/gobgp/v4 (Go) SEMVER:introduced=0,fixed=4.4.0; Osrg Gobgp < 4.4.0.
Is there a fix for CVE-2026-7737?
Yes. github.com/osrg/gobgp (Go): upgrade to 4.4.0 or later; github.com/osrg/gobgp/v4 (Go): upgrade to 4.4.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-7737 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-7737?
Check whether you run github.com/osrg/gobgp (Go), github.com/osrg/gobgp/v4 (Go) or Osrg Gobgp at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/osrg/gobgp (Go): upgrade to 4.4.0 or later
    go get github.com/osrg/gobgp@v4.4.0
  • github.com/osrg/gobgp/v4 (Go): upgrade to 4.4.0 or later
    go get github.com/osrg/gobgp/v4@v4.4.0

Technical details

An out-of-bounds read vulnerability exists in GoBGP's BMP (BGP Monitoring Protocol) parser within the 'pkg/packet/bmp/bmp.go' file. Specifically, the 'BMPPeerUpNotification.ParseBody' and 'BMPStatisticsReport.ParseBody' functions fail to validate the length of input data before reading fixed offsets from a data slice. While the internal 'parseBMPMessage' function utilizes a defer/recover mechanism to prevent immediate process crashes, these public methods can still be exploited via remote network packets to trigger panics or unexpected behavior. The issue is addressed in version 4.4.0 by adding explicit length checks (e.g., ensuring at least 4 bytes for Statistics Reports and 20 bytes for Peer Up Notifications) before field parsing.

Affected products

  • osrg GoBGP < 4.4.0

Identifiers

  • CVE-2026-7737
  • GHSA-w88c-9vg8-cmq8
  • GO-2026-5699

Timeline

  • 2026-04-01: patched: Version 4.4.0 released with fix.
  • 2026-05-04: disclosed: Initial disclosure and CVE assignment.
  • 2026-05-04: advisory

References

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