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Full vulnerability report · 2026
CVE-2026-47204High confidence

Envoy: grpc_stats filter segfault on Connect protocol requests to direct_response routes

envoyproxy · envoy

Official source article: GitHub GHSA-3JXH-8P6X-7PF6 ↗. Check the applicable product and release in the original source.

6.5MediumCVSS 3.1
Recommended action
Within 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:High, raised one band.upgradedsince 29 Jun 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • EPSS is 0.45% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs envoyproxy envoy and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 30 daysRemediation target: Within 180 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-47204 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityenvoy: Envoy: Denial of Service via Connect protocol request
1 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • openshift-service-mesh/proxyv2-rhel9 as a component of OpenShift Service Mesh 2
Summary
A flaw was found in Envoy, an open source edge and service proxy. A remote attacker can exploit this vulnerability by sending a specially crafted Connect protocol request to a direct response route. This action causes the `envoy.filters.http.grpc_stats` filter to crash, leading to a denial of service (DoS) for the Envoy process. This can disrupt services relying on the proxy.
Remediation
See Red Hat OpenShift Service Mesh 3.0.14 documentation at https://docs.redhat.com/en/documentation/red_hat_openshift_service_mesh/3.0
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-39824

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.26.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, the envoy.filters.http.grpc_stats filter crashes (null pointer dereference / segfault) when a Connect protocol request (Content-Type: application/connect+proto or application/connect+json) hits a direct_response route. A single unauthenticated HTTP request crashes the Envoy process. This vulnerability is fixed in 1.35.13, 1.36.9, 1.37.5, and 1.38.3.

What

Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.26.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, the envoy.filters.http.grpc_stats filter crashes (null pointer dereference / segfault) when a Connect protocol request (Content-Type: application/connect+proto or application/connect+json) hits a direct_response route. A single unauthenticated HTTP request crashes the Envoy process. This vulnerability is fixed in 1.35.13, 1.36.9, 1.37.5, and 1.38.3.

Why

The product dereferences a pointer that it expects to be valid but is NULL.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

What

Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.26.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, the envoy.filters.http.grpc_stats filter crashes (null pointer dereference / segfault) when a Connect protocol request (Content-Type: application/connect+proto or application/connect+json) hits a direct_response route. A single unauthenticated HTTP request crashes the Envoy process. This vulnerability is fixed in 1.35.13, 1.36.9, 1.37.5, and 1.38.3.

Why

The product dereferences a pointer that it expects to be valid but is NULL.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → NULL Pointer Dereference → disrupt the affected service
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-476 ↗

CWE-476: NULL Pointer Dereference. The product dereferences a pointer that it expects to be valid but is NULL.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkDenial of serviceCWE-476Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-2048Google Cloud Service Mesh und Envoy Proxy: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Google Cloud Service Mesh und Envoy Proxy ausnutzen, um einen Denial-of-Service-Zustand zu verursachen, Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen oder andere, nicht näher bezeichnete Angriffe durchzuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260701Security Bulletin 1 July 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 1 July 2026, published on 1 July 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-021144Envoy ProxyのEnvoyにおけるNULL ポインタデリファレンスに関する脆弱性

Envoyはクラウドネイティブアプリケーション向けに設計されたオープンソースのエッジおよびサービスプロキシです。バージョン1.26.0から1.35.13、1.36.9、1.37.5、および1.38.3までの間で、envoy.filters.http.grpc_statsフィルターはConnectプロトコルリクエスト（Content-Type: application/connect+protoまたはapplication/connect+json）がdirect_responseルートにヒットした際にクラッシュ（ヌルポインタ参照やセグフォルト）を引き起こします。認証されていない単一のHTTPリクエストによってEnvoyプロセスがクラッシュします。この脆弱性はバージョン1.35.13、1.36.9、1.37.5、および1.38.3で修正されています。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
openshift-service-mesh/proxyv2-rhel9 as a component of OpenShift Service Mesh 2
Fixed
Action
See Red Hat OpenShift Service Mesh 3.0.14 documentation at https://docs.redhat.com/en/documentation/red_hat_openshift_service_mesh/3.0
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 26 Jun 2026 · Last source change 29 Jun 2026, 13:27 UTC · CWE-476 · NULL Pointer Dereference

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-39824
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    >= 1.38.0, < 1.38.3; >= 1.37.0, < 1.37.5; >= 1.36.0, < 1.36.9; >= 1.26.0, < 1.35.13 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    >= 1.38.0, < 1.38.3; >= 1.37.0, < 1.37.5; >= 1.36.0, < 1.36.9; >= 1.26.0, < 1.35.13 · Fixed: See Red Hat OpenShift Service Mesh 3.0.14 documentation at https://docs.redhat.com/en/documentation/red_hat_openshift_service_mesh/3.0
    Red Hat Product Security ↗
  2. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2026-39824↗Red Hat Product Security security advisory↗CISA Vulnrichment SSVC evidence↗Public exploit reference · GitHub GHSA-3JXH-8P6X-7PF6↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-47204 · cve.blacktree.nl