CVE intelligence

CVE-2023-35945

Vulnerability intelligence

Published Jul 13, 2023Sources checked Oct 31, 2026

7.5HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2023-35945 and is rated High severity with a CVSS score of 7.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Oct 21, 2026

Vendor remediation details

CBL-Mariner Releases

Vendor-listed releases

18.17.1-2
1.46.0-3
3.21.4-8
16.20.2-2

CISA KEVNot listedBased on the latest collected catalog

EPSS1.7%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2023-35945?

Envoy is a cloud-native high-performance edge/middle/service proxy. Envoy’s HTTP/2 codec may leak a header map and bookkeeping structures upon receiving `RST_STREAM` immediately followed by the `GOAWAY` frames from an upstream server.

In nghttp2, cleanup of pending requests due to receipt of the `GOAWAY` frame skips de-allocation of the bookkeeping structure and pending compressed header. The error return [code path] is taken if connection is already marked for not sending more requests due to `GOAWAY` frame.

The clean-up code is right after the return statement, causing memory leak. Denial of service through memory exhaustion.

This vulnerability was patched in versions(s) 1.26.3, 1.25.8, 1.24.9, 1.23.11.

Source: NVD