{"cve":"CVE-2026-39825","nvd":{"published":"2026-05-07T20:16:43.390","modified":"2026-10-26T20:10:00.160","status":"Analyzed","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","score":5.3},"cwes":[],"references":["https://go.dev/cl/770541","https://go.dev/issue/78948","https://groups.google.com/g/golang-announce/c/qcCIEXso47M","https://pkg.go.dev/vuln/GO-2026-4976"],"products":["golang:go"],"source":"nvd","synced_at":"2026-10-26T20:34:58.897451322+00:00"},"epss":{"cve":"CVE-2026-39825","score":0.0039,"percentile":0.32913,"date":"2026-10-26"},"kev":null,"osv":[{"id":"GO-2026-4976","url":"https://osv.dev/vulnerability/GO-2026-4976","summary":"ReverseProxy forwards queries with more than urlmaxqueryparams parameters in net/http/httputil","modified":"2026-08-31T10:25:58.969613045Z","packages":[{"ecosystem":"Go","name":"stdlib","purl":"pkg:golang/stdlib","ranges":["<1.25.10",">=1.26.0-0 <1.26.3"],"fixed":["1.25.10","1.26.3"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}