CVE-2023-39325 — net
HIGHCVE-2023-39325 is a high-severity (CVSS 7.5) CWE-770 vulnerability in golang.org/x/net. A fix is available for golang.org/x/net — see the affected versions and patch details below.
HTTP/2 rapid reset can cause excessive work in net/http
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
CVE-2023-39325 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 377,333 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
golang.org/x/netReal-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
A malicious HTTP/2 client which rapidly creates requests and immediately resets them can cause excessive server resource consumption. While the total number of requests is bounded by the http2.Server.MaxConcurrentStreams setting, resetting an in-progress request allows the attacker to create a new request while the existing one is still executing. With the fix applied, HTTP/2 servers now bound the number of simultaneously executing handler goroutines to the stream concurrency limit (MaxConcurrentStreams). New requests arriving when at the limit (which can only happen after the client has reset an existing, in-flight request) will be queued until a handler exits. If the request queue grows too large, the server will terminate the connection. This issue is also fixed in golang.org/x/net/http2 for users manually configuring HTTP/2. The default stream concurrency limit is 250 streams (requests) per HTTP/2 connection. This value may be adjusted using the golang.org/x/net/http2 package; see the Server.MaxConcurrentStreams setting and the ConfigureServer function.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | golang.org/x/net | all versions | 0.17.0go get golang.org/x/net@v0.17.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for golang.org/x/net, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update golang.org/x/net to 0.17.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-39325 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 CVE-2023-39325 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-39325. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
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 CVE is related to CVE-2023-44487. The majority of RHEL utilities are not long-running applications; instead, they are command-line tools. These tools utilize Golang package as build-time dependency, which is why they are classified as having a "Moderate" level of impact. As go-lang vendors its dependencies, a…
| Product | Fixed in | Advisory |
|---|---|---|
| 3scale API Management 2.13 on RHEL 7 | 3scale-amp2/3scale-rhel7-operator:1.16.7-2 | RHEA-2023:7327 |
| CERT-MANAGER-1.11-RHEL-9 | cert-manager/cert-manager-operator-rhel9:v1.11.5-5 | RHSA-2023:6279 |
| CERT-MANAGER-1.12-RHEL-9 | cert-manager/cert-manager-operator-rhel9:v1.12.1-5 | RHSA-2023:6269 |
| Cryostat 2 on RHEL 8 | cryostat-tech-preview/cryostat-rhel8-operator:2.3.1-11 | RHSA-2023:6031 |
| Fence Agents Remediation 0.2 for RHEL 8 | workload-availability/fence-agents-remediation-rhel8-operator:v0.2.1-7 | RHSA-2023:6786 |
| Ironic content for Red Hat OpenShift Container Platform 4.12 | python-werkzeug-0:2.0.3-5.el9 | RHSA-2023:7610 |
| Ironic content for Red Hat OpenShift Container Platform 4.13 | openstack-ironic-1:21.3.1-0.20231106145533.e53dc4f.el9 | RHSA-2023:7325 |
| KDO-5.0-RHEL-9 | kube-descheduler-operator/descheduler-rhel9:v5.0-17 | RHSA-2024:0302 |
Frequently Asked Questions
Is CVE-2023-39325 in your dependencies?
O3 Security finds CVE-2023-39325 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.