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Full vulnerability report · 2025
CVE-2025-55162High confidence

Envoy: oAuth2 Filter Signout route will not clear cookies because of missing "secure;" flag

envoyproxy · envoy

Official source article: GitHub GHSA-95J4-HW7F-V2RH ↗. Check the applicable product and release in the original source.

6.3MediumCVSS 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 4 Sep 2025

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • EPSS is 0.34% 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-2025-55162 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityenvoyproxy/envoy: oAuth2 Filter Signout route will not clear cookies because of missing "secure;" flag
8 fixed

The vendor explicitly identifies these products or versions as containing the fix.

  • registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9@sha256:28e483cc6ded42fde9989fc16cb9a8c92750a8775b1af753e6ae7dc8ed3d379e_s390x as a component of Red Hat OpenShift Service Mesh 3.0
  • registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9@sha256:3759798960cd4981dba8fe934d51a439c836a0e0242fc81456304b5b13067d29_ppc64le as a component of Red Hat OpenShift Service Mesh 3.0
  • registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9@sha256:b1b03a3a39c6aac6279973e22755560138d584f1a87f0bc2333815d5e173f541_arm64 as a component of Red Hat OpenShift Service Mesh 3.0
  • registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9@sha256:bfb6528653e71c39a0c8b1ed5b47f470cdca34f19ea0fe97870ddf6e27b6e862_amd64 as a component of Red Hat OpenShift Service Mesh 3.0
  • registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9@sha256:1bf0f156d25d964e4aca4a512807c80712aa7d609c0e1d51890b9db007940173_s390x as a component of Red Hat OpenShift Service Mesh 3.1
  • registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9@sha256:54dc68f4cadf7da1f654879aae9a4472d37ed44461b5a27a430d1c717efc3dc2_amd64 as a component of Red Hat OpenShift Service Mesh 3.1
  • registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9@sha256:652e6fa688a5b7754aadc4361f4de413de2b294e2f06c58091021bb6fe662501_ppc64le as a component of Red Hat OpenShift Service Mesh 3.1
  • registry.redhat.io/openshift-service-mesh/istio-proxyv2-rhel9@sha256:9ae2a62ade185b68bc0243bc06ab59ffa77c1798da3dd434c61191caf5c8353b_arm64 as a component of Red Hat OpenShift Service Mesh 3.1
Summary
A flaw was found in Envoy. A session management flaw was discovered in how Envoy's OAuth2 filter handles user logouts. This could allow a user's session to remain active even after they have logged out, creating a risk of account hijacking on a shared computer.
Remediation
See Red Hat OpenShift Service Mesh 3.0.5 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-2025-26634

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 L7 proxy and communication bus designed for large modern service oriented architectures. In versions below 1.32.10 and 1.33.0 through 1.33.6, 1.34.0 through 1.34.4 and 1.35.0, insufficient Session Expiration in the Envoy OAuth2 filter leads to failed logout operations. When configured with __Secure- or __Host- prefixed cookie names, the filter fails to append the required Secure attribute to the Set-Cookie header during deletion. Modern browsers ignore this invalid request, causing the session cookie to persist. This allows a user to remain logged in after they believe they have logged out, creating a session hijacking risk on shared computers. The current implementation iterates through the configured cookie names to generate deletion headers but does not check for these prefixes. This failure to properly construct the deletion header means the user's session cookies are never removed by the browser, leaving the session active and allowing the next user of the same browser to gain unauthorized access to the original user's account and data. This is fixed in versions 1.32.10, 1.33.7, 1.34.5 and 1.35.1.

What

Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In versions below 1.32.10 and 1.33.0 through 1.33.6, 1.34.0 through 1.34.4 and 1.35.0, insufficient Session Expiration in the Envoy OAuth2 filter leads to failed logout operations. When configured with __Secure- or __Host- prefixed cookie names, the filter fails to append the required Secure attribute to the Set-Cookie header during deletion. Modern browsers ignore this invalid request, causing the session cookie to persist. This allows a user to remain logged in after they believe they have logged out, creating a session hijacking risk on shared computers. The current implementation iterates through the configured cookie names to generate deletion headers but does not check for these prefixes. This failure to properly construct the deletion header means the user's session cookies are never removed by the browser, leaving the session active and allowing the next user of the same browser to gain unauthorized access to the original user's account and data. This is fixed in versions 1.32.10, 1.33.7, 1.34.5 and 1.35.1.

Why

According to WASC, Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In versions below 1.32.10 and 1.33.0 through 1.33.6, 1.34.0 through 1.34.4 and 1.35.0, insufficient Session Expiration in the Envoy OAuth2 filter leads to failed logout operations. When configured with __Secure- or __Host- prefixed cookie names, the filter fails to append the required Secure attribute to the Set-Cookie header during deletion. Modern browsers ignore this invalid request, causing the session cookie to persist. This allows a user to remain logged in after they believe they have logged out, creating a session hijacking risk on shared computers. The current implementation iterates through the configured cookie names to generate deletion headers but does not check for these prefixes. This failure to properly construct the deletion header means the user's session cookies are never removed by the browser, leaving the session active and allowing the next user of the same browser to gain unauthorized access to the original user's account and data. This is fixed in versions 1.32.10, 1.33.7, 1.34.5 and 1.35.1.

Why

According to WASC, Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

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 → Insufficient Session Expiration → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
Required interaction required
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-613 ↗

CWE-613: Insufficient Session Expiration. According to WASC, Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization.

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:R/S:U/C:H/I:L/A:N

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.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.ILowIntegrity impact: A successful attack can cause a limited loss.ANoneAvailability impact: No direct loss is represented by this metric.
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.
NetworkCWE-613Public 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-2025-2085Red Hat OpenShift Service Mesh: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Red Hat OpenShift Service Mesh ausnutzen, um einen Denial of Service Angriff durchzuführen oder Userrechte zu erlangen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20250910Security Bulletin 10 SEP 2025

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 10 SEP 2025, published on 10 September 2025. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2025-013402Envoy Proxy の Envoy におけるセッション期限に関する脆弱性

Envoy Proxy の Envoy には、セッション期限に関する脆弱性が存在します。

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
envoy: >= 1.35.0, < 1.35.1, >= 1.34.0, < 1.34.5, >= 1.33.0, < 1.33.7, <= 1.32.0, < 1.32.10
Fixed
Action
See Red Hat OpenShift Service Mesh 3.0.5 documentation at https://docs.redhat.com/en/documentation/red_hat_openshift_service_mesh/3.0
Workaround
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04

Evidence and provenance

Published 3 Sept 2025 · Last source change 4 Sept 2025, 14:29 UTC · CWE-613 · Insufficient Session Expiration

CVE recordCVE.org · 5.1
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-2025-26634
Product sourceCNA
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD enriched

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
    >= 1.35.0, < 1.35.1; >= 1.34.0, < 1.34.5; >= 1.33.0, < 1.33.7; <= 1.32.0, < 1.32.10 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    >= 1.35.0, < 1.35.1; >= 1.34.0, < 1.34.5; >= 1.33.0, < 1.33.7; <= 1.32.0, < 1.32.10 · Fixed: See Red Hat OpenShift Service Mesh 3.0.5 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 Mitigation available to Patch available.
    Before
    Mitigation available
    After
    Patch available
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Mitigation reference recorded
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2025-26634↗Red Hat Product Security security advisory↗CISA Vulnrichment SSVC evidence↗Public exploit reference · GitHub GHSA-95J4-HW7F-V2RH↗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-2025-55162 · cve.blacktree.nl