CVE-2026-47220
Envoy: Segmentation fault when using %REQUESTED_SERVER_NAME% in log format
Description
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.
INFO
Published Date :
June 26, 2026, 7:16 p.m.
Last Modified :
July 15, 2026, 2:22 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c |
Solution
- Update Envoy to version 1.37.5 or later.
- Update Envoy to version 1.38.3 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-47220.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-47220 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-47220
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-47220 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-47220 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Jul. 15, 2026
Action Type Old Value New Value Changed Affected [{'cpes': ['cpe:/a:redhat:service_mesh:2'], 'vendor': 'Red Hat', 'product': 'OpenShift Service Mesh 2', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:service_mesh:3'], 'vendor': 'Red Hat', 'product': 'OpenShift Service Mesh 3', 'defaultStatus': 'unaffected'}] [{'cpes': ['cpe:/a:redhat:service_mesh:2'], 'vendor': 'Red Hat', 'product': 'OpenShift Service Mesh 2', 'packageName': 'openshift-service-mesh/proxyv2-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:service_mesh:3'], 'vendor': 'Red Hat', 'product': 'OpenShift Service Mesh 3', 'packageName': 'openshift-service-mesh/istio-proxyv2-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}] -
CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Jun. 30, 2026
Action Type Old Value New Value Added Affected [{'cpes': ['cpe:/a:redhat:service_mesh:2'], 'vendor': 'Red Hat', 'product': 'OpenShift Service Mesh 2', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:service_mesh:3'], 'vendor': 'Red Hat', 'product': 'OpenShift Service Mesh 3', 'defaultStatus': 'unaffected'}] Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-476 Added Reference https://access.redhat.com/security/cve/CVE-2026-47220 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2493652 Added Reference https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-47220.json -
Initial Analysis by [email protected]
Jun. 29, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* versions from (including) 1.37.0 up to (excluding) 1.37.5 *cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* versions from (including) 1.38.0 up to (excluding) 1.38.3 Added Reference Type GitHub, Inc.: https://github.com/envoyproxy/envoy/security/advisories/GHSA-j9wh-4qfm-wf2v Types: Exploit, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/envoyproxy/envoy/security/advisories/GHSA-j9wh-4qfm-wf2v Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 29, 2026
Action Type Old Value New Value Added Reference https://github.com/envoyproxy/envoy/security/advisories/GHSA-j9wh-4qfm-wf2v Added SSVC {'id': 'CVE-2026-47220', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-29T13:26:27.302143Z'} -
New CVE Received by [email protected]
Jun. 26, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'envoyproxy', 'product': 'envoy', 'versions': [{'status': 'affected', 'version': '>= 1.38.0, < 1.38.3'}, {'status': 'affected', 'version': '>= 1.37.0, < 1.37.5'}]}] Added Description 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-476 Added Reference https://github.com/envoyproxy/envoy/security/advisories/GHSA-j9wh-4qfm-wf2v