CVE-2026-78663

Double flow control refund on HTTP/2 server streams in net/http

CRITICAL 9.1

En bref

Source: NVD
EPSS: EPSS 0.62 % · centile 50 (2026-10-28)
État: PUBLISHED
Publiée: 2026-10-08 22:53 UTC
Mise à jour: 2026-10-09 16:42 UTC
Attribuée par: Go
Statut NVD: Awaiting Analysis

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.

Faiblesses (CWE)

CWE-675 — Multiple Operations on Resource in Single-Operation Context

Références

Scores

Version	Score	Vecteur	Évalué par
CVSS 3.1	CRITICAL 9.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H	CISA-ADP
CVSS 3.1	CRITICAL 9.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H	NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

Avis

GO-2026-6612 — Double flow control refund on HTTP/2 server streams in net/http

Références européennes

ENISA EUVD · EUVD-2026-95427
GCVE · GCVE-0-2026-78663

Avis du CERT-FR

CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr

Produits affectés

Produit	Versions
Go standard library · net/http	affected 0 < 1.26.9
Go standard library · net/http/internal/http2	affected 1.27.0-0 < 1.27.2
golang.org/x/net · golang.org/x/net/http2	affected 0 < 0.60.0

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)	Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD