VULNERABILITY INTELLIGENCE

CVE-2026-39825

CVSS score5.3 MEDIUM
EPSS probability0.39%
CISA KEVNot currently listed
Published2026-05-07
Last modified2026-10-26
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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.

Primary references