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.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

1.7% chance of exploitation in the next 30 days; higher than 76% of CVEs (scores of 2026-10-25)

CWEs

CWE-459, CWE-400

Published

2023-07-13

Modified

2026-10-15

Record from

the NVD, synced 2026-10-19

Affected

• envoyproxy:envoy
• nghttp2:nghttp2

References

• https://github.com/envoyproxy/envoy/security/advisories/GHSA-jfxv-29pc-x22r
• https://github.com/nghttp2/nghttp2/blob/e7f59406556c80904b81b593d38508591bb7523a/lib/nghttp2_session.c#L3346
• https://github.com/envoyproxy/envoy/security/advisories/GHSA-jfxv-29pc-x22r
• https://github.com/nghttp2/nghttp2/blob/e7f59406556c80904b81b593d38508591bb7523a/lib/nghttp2_session.c#L3346
• https://cert-portal.siemens.com/productcert/html/ssa-398330.html

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