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Fencer Vulns
high 7.5

CVE-2026-73512 json

Envoy: use-after-free in QUIC on internal redirects

published 2026-09-21 48 d ago modified 2026-10-06 33 d ago also BIT-envoy-2026-73512 , EUVD-2026-84113 , GHSA-r6j2-mrm5-72mg

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits
0
none known

Summary

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.

Patch / fix

  • bitnami envoy 1.36.10, 1.37.6, 1.38.4, 1.39.1
  • envoyproxy envoy 1.36.10, 1.37.6, 1.38.4, 1.39.1
  • istioctl openSUSE Tumbleweed 1.30.4-1.1

opensuse advisories openSUSE-SU-2026:11630-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-73512 updated cvss 7.5

envoy: envoy: HTTP/3 use-after-free when processing late datagrams

  • Red Hat OpenShift Service Mesh 3 openshift-service-mesh/istio-proxyv2-rhel9
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
47 d ago

Exploit prediction

0.87% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/envoyproxy/envoy/security/advisories/GHSA-r6j2-mrm5-72mg referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami envoy
<1.36.10
>=1.37.0, <1.37.6
>=1.38.0, <1.38.4
>=1.39.0, <1.39.1
1.36.10
1.37.6
1.38.4
1.39.1

Affected products

  • envoyproxy envoy

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.