EUVD Vulnerability Catalog

EUVD-2026-95427

Severity: CRITICAL Base Score: 9.1 CVSS Version: 3.1

Vulnerability Description

The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client can exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.

CVSS Vector Analysis

Below is the complete, human-readable breakdown of the CVSS metric string: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

▪ Attack Vector (AV): Network

▪ Attack Complexity (AC): Low

▪ Privileges Required (PR): None

▪ User Interaction (UI): None

▪ Scope (S): Unchanged

▪ Confidentiality Impact (C): None

▪ Integrity Impact (I): High

▪ Availability Impact (A): High

Affected Vendors & Systems

Vendor Go standard library

Vendor golang.org/x/net

References & Advisory Links

Metadata Profile

Database Authority

European Union Agency for Cybersecurity (ENISA) EUVD

Assigner

EPSS Probability

Known Aliases

CVE-2026-78663

Published On

2026-10-08

Last Updated

2026-10-09