GHSA-9rpw-2h95-666c is a high-severity (CVSS 7.5) Improper Input Validation vulnerability in github.com/cloudflare/goflow/v3. A fix is available for github.com/cloudflare/goflow/v3 — see the affected versions and patch details below.
Cloudflare GoFlow vulnerable to a Denial of Service in the sflow packet handling package
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 GHSA-9rpw-2h95-666c.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-9rpw-2h95-666c plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/cloudflare/goflow/v3Real-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
Impact
The sflow decode package prior to version 3.4.4 does not employ sufficient packet sanitisation which can lead to a denial of service attack. Attackers can craft malformed packets causing the process to consume huge amounts of memory resulting in a denial of service.
Specific Go Packages Affected
github.com/cloudflare/goflow/v3/decoders/sflow
Patches
Version 3.4.4 contains patches fixing this.
Workarounds
A possible workaround is to not have your goflow collector publicly reachable.
For more information
If you have any questions or comments about this advisory:
- Open an issue in goflow repo
- Email us netdev[@]cloudflare.com
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/cloudflare/goflow/v3 | all versions | 3.4.4go get github.com/cloudflare/goflow/v3@v3.4.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cloudflare/goflow/v3, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/cloudflare/goflow/v3 to 3.4.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9rpw-2h95-666c is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-9rpw-2h95-666c can be triaged on real exposure rather than presence alone.
Tailored to GHSA-9rpw-2h95-666c. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-9rpw-2h95-666c in your dependencies?
O3 Security finds GHSA-9rpw-2h95-666c across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.