CVE-2026-64676
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedKata Containers is an open source implementation of lightweight Virtual Machines (VMs) that perform like containers. In versions prior to 4.0.0, the kata-agent is vulnerable to an authorization bypass in confidential-guest memory management. In Confidential Containers (CoCo) deployments, the kata-agent enforces an OPA/Rego-based AgentPolicy that must authorize every ttRPC API call, forming the security boundary that prevents an untrusted host from directing the confidential guest. Two ttRPC methods introduced with the mem-agent feature are missing this authorization check, so an untrusted host can invoke them unconditionally regardless of the guest's policy configuration. When mem-agent is enabled (off by default), this lets the host tamper with in-guest memory management by forcing swap, aggressive eviction, or compaction, resulting in attacker-controlled availability and performance degradation of the confidential workload entirely outside the agent-policy boundary. The impact does not include memory disclosure or code execution, and severity is bounded by the precondition that mem-agent must be explicitly enabled. This issue is fixed in version 4.0.0.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisThe application checks who you are but not whether you're allowed to perform a given action, so any authenticated user can reach things meant for others. This is the classic “change the ID in the URL” bug. The fix is an authorization check on every request, evaluated against the acting user's permissions.
General guidance for the missing authorization class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped4.0.0
- 1. Identify the current Kata Containers version in use by checking the kata-agent package version (e.g., `kata-agent --version` or through the container runtime's metadata)
- 2. Confirm whether the mem-agent feature is enabled by reviewing the Kata Containers configuration files (typically in `/etc/kata-containers/` or within the runtime configuration)
- 3. If mem-agent is enabled, note that the vulnerability is exploitable; if disabled, the impact is limited but upgrading is still recommended for defense-in-depth
- 4. Upgrade the Kata Containers installation to version 4.0.0 or later by following the project's upgrade documentation for your deployment method (e.g., package manager, operator-based deployment, or manual installation)
- 5. After upgrading, verify the kata-agent version is 4.0.0 or later using `kata-agent --version`
- 6. Review and test the OPA/Rego AgentPolicy to ensure the authorization framework is functioning correctly for all ttRPC API calls
- 7. If using a package manager, commands may include: for Ubuntu/Debian `sudo apt-get update && sudo apt-get upgrade kata-containers`, for RHEL/CentOS `sudo yum update kata-containers`, or follow operator-based upgrade procedures for Kubernetes deployments
Generated from the published advisory — verify against the referenced sources before acting.
There is no version to upgrade to and no patch to apply. Every affected install stays exposed until the vendor ships a fix — or somebody else builds one.
Free. We build fixes in the order the community asks for them — and we’ll tell you the moment this one lands.
We develop and verify an original fix where the vendor hasn’t, from $1,600. Deployed to your staging first — never straight to production.
Scope it with usSee what else the community needs solved on the solutions-needed board.
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Free · runs locallyCheck whether your project pulls in CVE-2026-64676 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-64676 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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