CVE-2025-61726: Memory exhaustion in query parameter parsing in net/url

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-28 · updated 2026-09-17
Weakness: CWE-770

Description

The net/url package does not set a limit on the number of query parameters in a query. While the maximum size of query parameters in URLs is generally limited by the maximum request header size, the net/http.Request.ParseForm method can parse large URL-encoded forms. Parsing a large form containing many unique query parameters can cause excessive memory consumption.

Affected products

Go: before 1.24.12; from 1.25.0 before 1.25.6 — fixed in 1.24.12, 1.25.6

How to fix

Upgrade to a fixed version: Go 1.24.12, 1.25.6. Check the vendor advisory for mitigations.

References

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