CVE-2025-22870 — x/net
MEDIUMCVE-2025-22870 is a medium-severity (CVSS 4.4) CWE-115 vulnerability in golang.org/x/net. A fix is available for golang.org/x/net — see the affected versions and patch details below.
HTTP Proxy bypass using IPv6 Zone IDs in golang.org/x/net
Exploitation Status
No confirmed exploitation observed yet
- 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-2025-22870.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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
Matching of hosts against proxy patterns can improperly treat an IPv6 zone ID as a hostname component. For example, when the NO_PROXY environment variable is set to "*.example.com", a request to "[::1%25.example.com]:80` will incorrectly match and not be proxied.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | golang.org/x/net | all versions | 0.36.0go get golang.org/x/net@v0.36.0 |
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 0.36.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-22870 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.
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.
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-2025-22870 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| RHODF-4.18-RHEL-9 | odf4/cephcsi-operator-bundle:v4.18.3-4 | RHSA-2025:7616 |
| Cluster Observability Operator 1.5 | cluster-observability-operator/distributed-tracing-console-plugin-pf4-rhel9:1782840519 | RHSA-2026:34342 |
| Red Hat Developer Hub 1.7 | rhdh/rhdh-rhel9-operator:1.7.0-1754935808 | RHSA-2025:14090 |
| Red Hat Openshift Data Foundation 4.20 | odf4/cephcsi-rhel9:1774540992 | RHSA-2026:6503 |
| Red Hat Openshift Data Foundation 4.22 | odf4/cephcsi-rhel9:1782932114 | RHSA-2026:37387 |
Frequently Asked Questions
Is CVE-2025-22870 in your dependencies?
Find it across Go, including transitive dependencies.