CVE-2026-84304: gRPC-Go: Heap Memory Exhaustion (OOM) via HTTP/2 DATA Frame Fragmentation

highCVSS 7.5CVE-2026-84304

Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7.5
Published: 2026-09-08
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-84304

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-843040.41% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 35% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-84304	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for gRPC-Go

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

unknownCVE-2026-84445: gRPC-Go is the Go language implementation of gRPC. Prior to 1.82.2 and 1.83.2, servers created…nvd · 2026-09-14
high[UPDATE] [hoch] Red Hat OpenShift Container Platform (gRPC-Go): Schwachstelle ermöglicht Umgehen von Sicherhei…cert-bund · 2026-09-14
highGHSA-2v4p-qf9q-27wj: gRPC-Go xDS servers: Denial of Service (DoS) via crash due to missing `:authority` and `H…ghsa · 2026-09-08
mediumGHSA-qc2q-p7wx-3px3: gRPC-Go: xDS RBAC HTTP Filter bypass via mixed-case Header Matching and gRFC A41 validati…ghsa · 2026-09-08
unknownCVE-2026-84303: gRPC-Go: xDS RBAC HTTP Filter bypass via mixed-case Header Matching and gRFC A41 validation ev…msrc · 2026-09-08
highGHSA-vp52-pcj8-j9qc: gRPC-Go: Heap Memory Exhaustion (OOM) via HTTP/2 DATA Frame Fragmentationghsa · 2026-09-01