nodejs undici prior 6.28.0/7.29.0/8.9.0 crlf injection

Summaryinfo

A vulnerability labeled as critical has been found in nodejs undici. Affected by this vulnerability is an unknown functionality. Such manipulation leads to crlf injection. This vulnerability is documented as CVE-2026-15157. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in nodejs undici and classified as critical. Affected by this issue is an unknown part. The manipulation with an unknown input leads to a crlf injection vulnerability. Using CWE to declare the problem leads to CWE-93. The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-15157 since 07/08/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available.

Upgrading to version 6.28.0, 7.29.0 or 8.9.0 eliminates this vulnerability.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

• nodejs

Name

• undici

Website

• Product: https://github.com/nodejs/undici/

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion