CVE-2026-42283
HIGHCVE-2026-42283 is a high-severity (CVSS 7.7) vulnerability in github.com/loft-sh/devspace. O3 Security confirms whether CVE-2026-42283 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
DevSpace UI Server WebSocket CheckOrigin does not validate source
Blast Radius
github.com/loft-sh/devspaceReal-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
DevSpace is a client-only developer tool for cloud-native development with Kubernetes. Prior to 6.3.21, DevSpace's UI server WebSocket accepts connections from all origins by default, and therefore several endpoints are exposed via this WebSocket. When a developer runs the DevSpace UI and at the same time uses a browser to access the internet, a malicious website they visit can use their browser to establish a cross-origin WebSocket connection to ws://127.0.0.1:8090. This vulnerability is fixed in 6.3.21.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/loft-sh/devspace | ≥ 6.3.20&&< 6.3.21 | 6.3.21 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/loft-sh/devspace. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/loft-sh/devspace to 6.3.21 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-42283 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 pinpoints whether CVE-2026-42283 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-42283. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-42283 in your dependencies?
O3 detects CVE-2026-42283 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.