Description
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's HttpDatagramHandler caches the current RequestDecoder when Capsule Protocol is enabled. Stream recreation, including an internal redirect, replaces the ActiveStream and updates EnvoyQuicServerStream but does not update the handler's cached pointer. A subsequent HTTP/3 datagram can call decodeData through the freed decoder, causing invalid virtual dispatch and a process crash. The relevant scope boundary is that hTTP/3 datagrams and Capsule Protocol must be enabled, and the request must enter a stream-recreation path such as an internal redirect. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
Published: 2026-09-21
Score: 7.5 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Mon, 21 Sep 2026 20:00:00 +0000

Type Values Removed Values Added
Description No description is available for this CVE. Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's HttpDatagramHandler caches the current RequestDecoder when Capsule Protocol is enabled. Stream recreation, including an internal redirect, replaces the ActiveStream and updates EnvoyQuicServerStream but does not update the handler's cached pointer. A subsequent HTTP/3 datagram can call decodeData through the freed decoder, causing invalid virtual dispatch and a process crash. The relevant scope boundary is that hTTP/3 datagrams and Capsule Protocol must be enabled, and the request must enter a stream-recreation path such as an internal redirect. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
Title envoy: envoy: HTTP/3 use-after-free when processing late datagrams Envoy: use-after-free in QUIC on internal redirects
References

Wed, 02 Sep 2026 22:15:00 +0000

Type Values Removed Values Added
First Time appeared Envoyproxy
Envoyproxy envoy
Vendors & Products Envoyproxy
Envoyproxy envoy

Tue, 01 Sep 2026 12:15:00 +0000

Type Values Removed Values Added
Description No description is available for this CVE.
Title envoy: envoy: HTTP/3 use-after-free when processing late datagrams
Weaknesses CWE-416
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Important


Subscriptions

Envoyproxy Envoy
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-21T19:51:23.229Z

Reserved: 2026-08-12T19:00:33.736Z

Link: CVE-2026-73512

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-21T20:17:27.647

Modified: 2026-09-21T20:17:27.647

Link: CVE-2026-73512

cve-icon Redhat

Severity : Important

Publid Date: 2026-08-26T13:00:00Z

Links: CVE-2026-73512 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-21T22:30:12Z

Weaknesses