CVE-2026-55997
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 · uneditedRancher issues long-lived registration tokens to authenticate nodes and agents joining a downstream cluster. These tokens were stored and exposed in plaintext with no expiration, so a malicious user could obtain one either through the Rancher API, etcd, stored automation, or direct file access on a node, and could use it at any time to register a rogue node into the cluster.
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 analysis · high confidenceRancher stores long-lived node/agent registration tokens in plaintext with no expiration. Attackers with access to the Rancher API, etcd, stored automation, or node file systems can retrieve these tokens and use them at any time to register unauthorized (rogue) nodes into downstream clusters.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Rancher versionRun 'rancher --version' or check the Rancher UI under 'Support' page to determine the installed version. Compare against the affected version range for this CVE.Affected if Installed version falls within the affected version range and has node/agent registration tokens configured.
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List active node registration tokensUse Rancher API or UI to query /v3/clusterregistrationtokens or navigate to cluster settings to view all node registration tokens. Note their creation dates and status.Affected if Long-lived tokens exist without expiration dates, especially those created before token expiration policies were implemented.
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Verify token expiration settingsInspect each node registration token's properties via Rancher API: GET /v3/clusterregistrationtokens/{id} - check for 'ttl' (time-to-live) or 'expiresAt' fields.Affected if Tokens show no ttl value, null expiresAt, or expiration dates far in the future (years).
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Examine etcd for plaintext tokensIf you have etcd access, run 'etcdctl get /rancher/clusterRegistrationTokens/' or similar prefix searches to enumerate stored token data. Check token values stored in etcd.Affected if Tokens are stored in plaintext without encryption in etcd.
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Check cluster automation and node filesReview Rancher-backed cluster provisioning automation, node driver configs, and any stored scripts for embedded token values. Look in Rancher project secrets or configmaps.Affected if Registration tokens appear in plaintext within configuration files, automation scripts, or persistent storage.
A user is affected if their Rancher installation contains node/agent registration tokens stored in plaintext with no expiration or with expiration set far in the future, especially if accessed via etcd, API, or stored automation.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataImplement token expiration/rotation and encrypt tokens at rest. Audit and revoke existing plaintext tokens, then enforce time-limited tokens with automatic rotation for all future node registrations.
- Consultation12.0 h
- Implementation80.0 h
- Testing24.0 h
- Review / QA16.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $37,248.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-55997 — 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-2026-55997 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
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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