Openstack MistralApplication · Redhat
CVE-2018-16848
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 · uneditedA Denial of Service (DoS) condition is possible in OpenStack Mistral in versions up to and including 7.0.3. Submitting a specially crafted workflow definition YAML file containing nested anchors can lead to resource exhaustion culminating in a denial of service.
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 confidenceOpenStack Mistral versions up to 7.0.3 are vulnerable to a denial of service attack via specially crafted YAML workflow definitions containing nested anchors. When the Mistral service parses such malicious YAML files, the nested anchors cause excessive resource consumption (likely exponential parsing complexity), leading to service unavailability.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Openstack MistralApplication
<= 7.0.3CVSS 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
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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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Determine Mistral versionRun the command to query the installed Mistral package version (e.g., rpm -q openstack-mistral or pip show mistral), then compare the version number to the affected range: any version <= 7.0.3 is vulnerable.Affected if Installed version is 7.0.3 or lower.
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Confirm Mistral service is activeCheck if the Mistral service is currently running (e.g., systemctl status mistral or ps aux | grep mistral).Affected if Mistral service is running.
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Identify workflow storage locationLocate where Mistral workflow YAML files are stored, typically in the /var/lib/mistral directory or a custom workflows path configured in mistral.conf under [api] workflow_dir.Affected if YAML workflow files are present and being processed.
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Inspect workflows for nested anchorsExamine YAML workflow definition files for the presence of nested anchor syntax (e.g., &anchor definitions referencing other anchors like &a *a or deeply nested &ref *ref patterns).Affected if Any workflow YAML file contains nested anchors (anchors that reference themselves or other anchors in a recursive pattern).
You are affected if Mistral version 7.0.3 or lower is installed and running while processing YAML workflow definitions that contain nested anchors.
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 dataUpgrade Mistral to version 7.0.4 or later, which contains the fix for this vulnerability. As a temporary workaround, implement input validation to reject YAML files with nested anchors before processing.
Fix this in Openstack Mistral
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-16848 — 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-2018-16848 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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- Version or environment caveats, and links to real fixes
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