CVE-2026-15157
4.2 · MEDIUMOverview
CVE-2026-15157 is a medium-severity vulnerability affecting nodejs undici. It was published on July 29, 2026 and has a CVSS 3.1 base score of 4.2 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 4.2, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
undici does not validate the type property of a duck-typed blob-like request body before using it as the Content-Type header on the HTTP/1.1 dispatcher. In undici before 6.28.0, from 7.0.0 up to before 7.29.0, and from 8.0.0 up to before 8.9.0, an application that passes a hand-rolled blob-like body (via request, stream, pipeline, or dispatch) whose type is derived from untrusted input allows an attacker to inject CRLF sequences and append arbitrary HTTP headers, potentially smuggling a second request past the upstream. Native Blob objects are safe because their constructor strips CRLF from the type, and fetch is unaffected because it validates headers, but ecosystem libraries that build duck-typed blob shapes from user input can reach the vulnerable path. This is the same defect class as CVE-2022-35948 and CVE-2026-1527, on a header sink that the earlier fixes did not cover. The issue is fixed in undici 6.28.0, 7.29.0, and 8.9.0.
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, < 6.28.0 | Affected |
Frequently Asked Questions
What is CVE-2026-15157?
CVE-2026-15157 is a medium-severity vulnerability affecting nodejs undici. It was published on July 29, 2026 and has a CVSS 3.1 base score of 4.2 (MEDIUM).
How severe is CVE-2026-15157?
This vulnerability has a CVSS 3.1 base score of 4.2, 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-2026-15157?
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-2026-15157?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-15157 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
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