CVE-2026-58055
5.4 · MEDIUMOverview
CVE-2026-58055 is a medium-severity vulnerability affecting nghttp2 nghttp2. It was published on June 28, 2026 and has a CVSS 3.1 base score of 5.4 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.4, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
nghttp2's nghttpx proxy through 1.69.0 forwards an HTTP/1.1 Upgrade request that also carries a Content-Length header and body onto reusable keep-alive backend connections, re-adding the Upgrade and Connection headers while passing Content-Length verbatim. A backend that resolves the resulting ambiguous message in the attacker's favor enables HTTP request/response smuggling and cross-client response-queue poisoning.
Remediation
Check the references section for vendor advisories and patches from nghttp2. Update nghttp2 to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| nghttp2 | nghttp2 | 0 | Affected |
References
Frequently Asked Questions
What is CVE-2026-58055?
CVE-2026-58055 is a medium-severity vulnerability affecting nghttp2 nghttp2. It was published on June 28, 2026 and has a CVSS 3.1 base score of 5.4 (MEDIUM).
How severe is CVE-2026-58055?
This vulnerability has a CVSS 3.1 base score of 5.4, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-58055?
Check the references section for vendor advisories and patches from nghttp2. Update nghttp2 to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-58055?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-58055 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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