http-proxy-middleware is node.js http-proxy middleware. From 3.0.4 until 3.0.7 and 4.1.1, fixRequestBody() is the library's documented helper for re-emitting a request body that was already consumed by a body parser. When the outgoing Content-Type is multipart/form-data, it rebuilds the body with handlerFormDataBodyData(), which interpolates each req.body key and value directly into the multipart wire format without neutralizing CR/LF. A \r\n inside a value (or key) lets an attacker close the current part and inject an entirely new form part. Because the proxy's own body parser saw a single opaque value, any gateway-side policy or validation performed on req.body is evaluated against a different set of fields than the upstream backend ultimately parses a request/parameter desynchronization across the trust boundary. This vulnerability is fixed in 3.0.7 and 4.1.1.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - http-proxy-middleware is node.js http-proxy middleware. From 3.0.4 until 3.0.7 and 4.1.1, fixRequestBody()
    is the library's documented helper for re-emitting a request body that was already consumed by a body
    parser. When the outgoing Content-Type is multipart/form-data, it rebuilds the body with
    handlerFormDataBodyData(), which interpolates each req.body key and value directly into the multipart wire
    format without neutralizing CR/LF. A \r\n inside a value (or key) lets an attacker close the current part
    and inject an entirely new form part. Because the proxy's own body parser saw a single opaque value, any
    gateway-side policy or validation performed on req.body is evaluated against a different set of fields
    than the upstream backend ultimately parses a request/parameter desynchronization across the trust
    boundary. This vulnerability is fixed in 3.0.7 and 4.1.1. (CVE-2026-55603)

ID	Name	Product	Family	Type	Severity
463675	Echo: http-proxy-middleware: security update to 3.0.7	Tenable Cloud Security	Echo Local Security Checks	Local	high
463675	Echo: http-proxy-middleware: security update to 3.0.7	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	high
443872	SCA: security update for http-proxy-middleware (GHSA-gcq2-9pq2-cxqm)	Tenable Cloud Security	SCA Checks	Local	high
443872	SCA: security update for http-proxy-middleware (GHSA-gcq2-9pq2-cxqm)	Tenable Self-Hosted Container Security	SCA Checks	Local	high

Detections

Analytics

CVE-2026-55603

high

Tenable Plugins

high

high

high

high