CVE-2026-39825: ReverseProxy forwards queries with more than urlmaxqueryparams parameters in net/http/httputil
Go standard library · net/http/httputil
Vendor fix available · Affected: Go standard library net/http/httputil · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 33% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Go standard library · net/http/httputilbefore 1.25.10; from 1.26.0-0 before 1.26.3
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- Go standard library
- Published
- May 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-39825 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.