CVE-2026-1527
4.6 · MEDIUMOverview
CVE-2026-1527 is a medium-severity vulnerability affecting nodejs undici. It was published on March 12, 2026 and has a CVSS 3.1 base score of 4.6 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 4.6, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
ImpactWhen an application passes user-controlled input to the upgrade option of client.request(), an attacker can inject CRLF sequences (\r\n) to:
* Inject arbitrary HTTP headers
* Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch)
The vulnerability exists because undici writes the upgrade value directly to the socket without validating for invalid header characters:
// lib/dispatcher/client-h1.js:1121
if (upgrade) {
header += `connection: upgrade\r\nupgrade: ${upgrade}\r\n`
}
Remediation
Check the references section for vendor advisories and patches from nodejs. Update undici 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 |
|---|---|---|---|
| nodejs | undici | >= 0, < 6.24.0 | Affected |
Frequently Asked Questions
What is CVE-2026-1527?
CVE-2026-1527 is a medium-severity vulnerability affecting nodejs undici. It was published on March 12, 2026 and has a CVSS 3.1 base score of 4.6 (MEDIUM).
How severe is CVE-2026-1527?
This vulnerability has a CVSS 3.1 base score of 4.6, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-1527?
Check the references section for vendor advisories and patches from nodejs. Update undici 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-2026-1527?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-1527 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.
Automated penetration testing that runs continuously, not just quarterly.
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Browser-based exploitation validates findings with real proof-of-concept.
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