ReverseProxy can forward queries containing parameters not visible to Rewrite functions. When used with a Rewrite function, or a Director function which parses query parameters, ReverseProxy sanitizes the forwarded request to remove query parameters which are not parsed by url.ParseQuery. ReverseProxy does not take ParseQuery's limit on the total number of query parameters (controlled by GODEBUG=urlmaxqueryparams=N) into account. This can permit ReverseProxy to forward a request containing a query parameter that is not visible to the Rewrite function. For example, the query "a1=x&a2=x&...&a10000=x&hidden=y" can forward the parameter "hidden=y" while hiding it from the proxy's Rewrite function.
History

Thu, 07 May 2026 22:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20

Thu, 07 May 2026 20:00:00 +0000

Type Values Removed Values Added
Description ReverseProxy can forward queries containing parameters not visible to Rewrite functions. When used with a Rewrite function, or a Director function which parses query parameters, ReverseProxy sanitizes the forwarded request to remove query parameters which are not parsed by url.ParseQuery. ReverseProxy does not take ParseQuery's limit on the total number of query parameters (controlled by GODEBUG=urlmaxqueryparams=N) into account. This can permit ReverseProxy to forward a request containing a query parameter that is not visible to the Rewrite function. For example, the query "a1=x&a2=x&...&a10000=x&hidden=y" can forward the parameter "hidden=y" while hiding it from the proxy's Rewrite function.
Title ReverseProxy forwards queries with more than urlmaxqueryparams parameters in net/http/httputil
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Go

Published:

Updated: 2026-05-07T19:41:18.453Z

Reserved: 2026-04-07T18:13:03.527Z

Link: CVE-2026-39825

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-07T20:16:43.390

Modified: 2026-05-07T20:38:04.860

Link: CVE-2026-39825

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-07T22:00:12Z