CVE-2026-39825

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.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://go.dev/cl/770541	Patch
https://go.dev/issue/78948	Issue Tracking
https://groups.google.com/g/golang-announce/c/qcCIEXso47M	Release Notes
https://pkg.go.dev/vuln/GO-2026-4976	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:golang:go::::::::
	cpe:2.3:a:golang:go::::::::

History

No history.

Information

Published : 2026-05-07 20:16

Updated : 2026-06-17 10:42

NVD link : CVE-2026-39825

Mitre link : CVE-2026-39825

CVE.ORG link : CVE-2026-39825

JSON object : View

Products Affected

golang

go

CWE

NVD-CWE-noinfo

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