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Full vulnerability report · 2026
CVE-2026-41326High confidence

Kata Containers: CopyFile Policy Subversion via Symlinks

kata-containers · kata-containers

8.2HighCVSS 4.0
Recommended action
Within 7 days

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

Patch available
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-2026-41326 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitykata-containers: Arbitrary file write inside guest image via CopyFile policy
2 known affected

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

  • openshift-sandboxed-containers/osc-podvm-payload-rhel9 as a component of Confidential Compute Attestation
  • openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4
Summary
A flaw was found in Kata Containers. An oversight in the CopyFile policy (and perhaps the CopyFile handler) allows untrusted hosts to write to arbitrary locations inside the guest workload image. This can be used to overwrite binaries inside the guest and exfiltrate data from containers; even those running inside CVMs.
Remediation
For OpenShift Container Platform 4.19 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this asynchronous errata update: https://docs.redhat.com/en/documentation/openshift_container_platform/4.19/html/release_notes/ You may download the oc tool and use it to inspect release image metadata for x86_64, s390x, ppc64le, and aarch64 architectures. The image digests may be found at https://quay.io/repository/openshift-release-dev/ocp-release?tab=tags. The sha values for the release are as follows: (For x86_64 architecture) The image digest is sha256:12ba901e472743bd79695772e65a451ac80ac29200cc06076471c42ed0956675 (For s390x architecture) The image digest is sha256:33b55b92bbc4790ac37d4c7b11d1931a2240510799c38c1eca5aeb56aa7e3340 (For ppc64le architecture) The image digest is sha256:3f3b589bf1ba5601644293d48f27ebf26cce0af703edde58001cf88f25066808 (For aarch64 architecture) The image digest is sha256:sha256:c5b6085ebfabad3ca4a7bcf4c0a86bb7c1c2454333a3a75859eb0e7b85a609ee All OpenShift Container Platform 4.19 users are advised to upgrade to these updated packages and images when they are available in the appropriate release channel. To check for available updates, use the OpenShift CLI (oc) or web console. Instructions for upgrading a cluster are available at https://docs.redhat.com/en/documentation/openshift_container_platform/4.19/html-single/updating_clusters/index#updating-cluster-cli.
Optional official sources

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

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

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-2026-25611

No EUVD known-exploited evidence

Kata Containers is an open source project focusing on a standard implementation of lightweight Virtual Machines (VMs) that perform like containers. From v3.4.0 to v3.28.0, an oversight in the CopyFile policy (and perhaps the CopyFile handler) allows untrusted hosts to write to arbitrary locations inside the guest workload image. This can be used to overwrite binaries inside the guest and exfiltrate data from containers; even those running inside CVMs. This vulnerability is fixed in v3.29.0.

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
8.2 · CVSS 4.0
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High 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

Kata Containers is an open source project focusing on a standard implementation of lightweight Virtual Machines (VMs) that perform like containers. From v3.4.0 to v3.28.0, an oversight in the CopyFile policy (and perhaps the CopyFile handler) allows untrusted hosts to write to arbitrary locations inside the guest workload image. This can be used to overwrite binaries inside the guest and exfiltrate data from containers; even those running inside CVMs. This vulnerability is fixed in v3.29.0.

What

Kata Containers is an open source project focusing on a standard implementation of lightweight Virtual Machines (VMs) that perform like containers. From v3.4.0 to v3.28.0, an oversight in the CopyFile policy (and perhaps the CopyFile handler) allows untrusted hosts to write to arbitrary locations inside the guest workload image. This can be used to overwrite binaries inside the guest and exfiltrate data from containers; even those running inside CVMs. This vulnerability is fixed in v3.29.0.

Why

The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.

How

An attacker operating through local access may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Kata Containers is an open source project focusing on a standard implementation of lightweight Virtual Machines (VMs) that perform like containers. From v3.4.0 to v3.28.0, an oversight in the CopyFile policy (and perhaps the CopyFile handler) allows untrusted hosts to write to arbitrary locations inside the guest workload image. This can be used to overwrite binaries inside the guest and exfiltrate data from containers; even those running inside CVMs. This vulnerability is fixed in v3.29.0.

Why

The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.

How

An attacker operating through local access may attempt exploitation without authentication or user interaction. 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

CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.

Likely attack path
local access → UNIX Symbolic Link (Symlink) Following → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-61 ↗

CWE-61: UNIX Symbolic Link (Symlink) Following. The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:H/SI:N/SA:N

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCHighSubsequent-system confidentiality: A successful attack can cause a major loss.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
UnauthenticatedCWE-61Public exploit reference
A

Official authority intelligence

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

ENISA EUVD · EUVD-2026-25611Official EUVD mapping

Kata Containers is an open source project focusing on a standard implementation of lightweight Virtual Machines (VMs) that perform like containers. From v3.4.0 to v3.28.0, an oversight in the CopyFile policy (and perhaps the CopyFile handler) allows untrusted hosts to write to arbitrary locations inside the guest workload image. This can be used to overwrite binaries inside the guest and exfiltrate data from containers; even those running inside CVMs. This vulnerability is fixed in v3.29.0.

Official EUVD record
CERT-FR · French · CERTFR-2026-AVI-0781Multiples vulnérabilités dans le noyau Linux de Red Hat

d?id=CVE-2026-31532 Référence CVE CVE-2026-31669 https://www.cve.org/CVERecord?id=CVE-2026-31669 Référence CVE CVE-2026-31685 https://www.cve.org/CVERecord?id=CVE-2026-31685 Référence CVE CVE-2026-31786 https://www.cve.org/CVERecord?id=CVE-2026-31786 Référence CVE CVE-2026-31787 https://www.cve.org/CVERecord?id=CVE-2026-31787 Référence CVE CVE-2026-35385 https://www.cve.org/CVERecord?id=CVE-2026-35385 Référence CVE CVE-2026-39979 https://www.cve.org/CVERecord?id=CVE-2026-39979 Référence CVE CVE-2026-40164 https://www.cve.org/CVERecord?id=CVE-2026-40164 Référence CVE CVE-2026-41035 https://www.cve.org/CVERecord?id=CVE-2026-41035 Référence CVE CVE-2026-41326 https://www.cve.org/CVERecord?id=CVE-2026-41326 Référence CVE CVE-2026-43037 https://www.cve.org/CVERecord?id=CVE-2026-43037 Référence CVE CVE-2026-43038 https://www.cve.org/CVERecord?id=CVE-2026-43038 Référence CVE CVE-2026-43110 https://www.cve.org/CVERecord?id=CVE-2026-43110 Référence CVE CVE-2026-43116 https://www.cve.org/CVERecord?id=CVE-2026-43116 Référence CVE CVE-2026-43158 https://www.cve.org/CVERecord?id=CVE-2026-43158 Référence CVE CVE-2026-43163 https://www.cve.org/CVERecord?id=CVE-2026-43163 Référence CVE CVE-2026-43190 https://www.cve.org/CVERecord?id=CVE-2026-43190 Référence CVE CVE-2026-43303 https://www.cve.org/CVERecord?id=

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-sandboxed-containers/osc-podvm-payload-rhel9 as a component of Confidential Compute Attestation; openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4
Fixed
rhcos-aarch64-4.19.9.6.202606100451-0 as a component of Red Hat OpenShift Container Platform 4.19; rhcos-ppc64le-4.19.9.6.202606100451-0 as a component of Red Hat OpenShift Container Platform 4.19; rhcos-s390x-4.19.9.6.202606100451-0 as a component of Red Hat OpenShift Container Platform 4.19; rhcos-x86_64-4.19.9.6.202606100451-0 as a component of Red Hat OpenShift Container Platform 4.19
Action
For OpenShift Container Platform 4.19 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this asynchronous errata update: https://docs.redhat.com/en/documentation/openshift_container_platform/4.19/html/release_notes/ You may download the oc tool and use it to inspect release image metadata for x86_64, s390x, ppc64le, and aarch64 architectures. The image digests may be found at https://quay.io/repository/openshift-release-dev/ocp-release?tab=tags. The sha values for the release are as follows: (For x86_64 architecture) The image digest is sha256:12ba901e472743bd79695772e65a451ac80ac29200cc06076471c42ed0956675 (For s390x architecture) The image digest is sha256:33b55b92bbc4790ac37d4c7b11d1931a2240510799c38c1eca5aeb56aa7e3340 (For ppc64le architecture) The image digest is sha256:3f3b589bf1ba5601644293d48f27ebf26cce0af703edde58001cf88f25066808 (For aarch64 architecture) The image digest is sha256:sha256:c5b6085ebfabad3ca4a7bcf4c0a86bb7c1c2454333a3a75859eb0e7b85a609ee All OpenShift Container Platform 4.19 users are advised to upgrade to these updated packages and images when they are available in the appropriate release channel. To check for available updates, use the OpenShift CLI (oc) or web console. Instructions for upgrading a cluster are available at https://docs.redhat.com/en/documentation/openshift_container_platform/4.19/html-single/updating_clusters/index#updating-cluster-cli.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 24 Apr 2026 · Last source change 1 Sept 2026, 12:04 UTC · CWE-61 · UNIX Symbolic Link (Symlink) Following

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-2026-25611
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 →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-25611↗Vendor CSAF · Red Hat Product Security↗CISA Vulnrichment SSVC evidence↗Patch or update reference↗CVE authority or vendor reference↗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-2026-41326 · cve.blacktree.nl