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Fencer Vulns
high 7.5

CVE-2026-47220 json

Envoy: Segmentation fault when using %REQUESTED_SERVER_NAME% in log format

published 2026-06-26 4 mo ago modified 2026-10-25 14 d ago also BIT-envoy-2026-47220 , EUVD-2026-39829 , GHSA-j9wh-4qfm-wf2v

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 52%
public exploits
0
none known

Summary

Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.37.0 until 1.37.5 and 1.38.3, when the %REQUESTED_SERVER_NAME(X:Y)% is used in log format and host related options is specified, like HOST_FIRST, SNI_FIRST, it's possible to crash Envoy when the specified host header is missing in the request headers. This vulnerability is fixed in 1.37.5 and 1.38.3.

Patch / fix

  • bitnami envoy 1.37.5, 1.38.3
  • envoyproxy envoy 1.37.5, 1.38.3
  • istioctl openSUSE Tumbleweed 1.30.2-1.1

opensuse advisories openSUSE-SU-2026:11141-1

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-2026-47220 updated cvss 7.5

envoy: Envoy: Denial of Service via missing host header in specific logging configurations

  • Red Hat OpenShift Service Mesh 2 openshift-service-mesh/proxyv2-rhel9 Red Hat OpenShift Service Mesh 3 openshift-service-mesh/istio-proxyv2-rhel9
    not affected: vulnerable code 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
4 mo ago

Exploit prediction

0.66% chance of exploitation in the next 30 days, higher than 52% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/envoyproxy/envoy/security/advisories/GHSA-j9wh-4qfm-wf2v 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
CISA ADP 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
>=1.37.0, <1.37.5
>=1.38.0, <1.38.3
1.37.5
1.38.3

Affected products

  • envoyproxy envoy
  • Red Hat OpenShift Service Mesh 2
  • Red Hat OpenShift Service Mesh 3

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.