CVE-2026-37462 is a high-severity (CVSS 7.5) CWE-190 vulnerability in github.com/osrg/gobgp/v4. A fix is available for github.com/osrg/gobgp/v4 — see the affected versions and patch details below.
GoBGP: Integer underflow in the BGPUpdate.DecodeFromBytes function
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-37462.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-37462 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 380,066 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
github.com/osrg/gobgp/v4Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/osrg/gobgp/v4 | all versions | 4.4.0go get github.com/osrg/gobgp/v4@v4.4.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/osrg/gobgp/v4, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/osrg/gobgp/v4 to 4.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-37462 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This Important flaw in gobgp allows a remote, unauthenticated attacker to trigger a denial of service. By sending a specially crafted BGP UPDATE message, an integer underflow can occur, disrupting network operations and impacting the availability of services that rely on gobgp, such as those deployed within OpenShift…
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.Source: Red Hat security advisory for CVE-2026-37462 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-37462 in your dependencies?
Find it across Go, including transitive dependencies.