CVE-2026-49299
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 · uneditedIn OpenStack Neutron before 28.0.1, the tagging controller enforces plural policy action names on single-tag write operations while the defined policy rules use singular names. The mismatched names evaluate as allowed under the default policy, permitting a project reader to create and update tags on same-project resources. Deployments running Neutron 26.0.0 or later are affected.
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 Neutron's tagging controller enforces plural policy action names (e.g., 'tags') on single-tag write operations, while the defined policy rules use singular names (e.g., 'tag'). This naming mismatch causes the mismatched policy checks to evaluate as allowed under the default policy, permitting project readers to create and update tags on resources within their project when they should only have read access.
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
- Network
- Complexity
- Low
- Privileges
- Low
- Authentication
- X
- User interaction
- None
- Scope
- X
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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 Neutron versionRun `neutron --version` or check the installed package version via your package manager (e.g., `pip show neutron`, `rpm -q neutron`, `dpkg -l neutron`).Affected if The installed version is before 28.0.1.
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Locate Neutron policy configurationFind the policy.json or policy.yaml file. Common paths include /etc/neutron/policy.json, /etc/neutron/policy.yaml, or within the Neutron service configuration directory. Check the file referenced by the `policy_file` option in neutron.conf.Affected if The policy configuration file exists and is in use.
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Inspect tag operation policy rulesOpen the policy configuration file and search for entries related to tag operations. Look for rules using both singular 'tag' and plural 'tags' forms, particularly for create/update operations.Affected if The policy rules define only singular forms (e.g., 'tag') but the controller code references plural forms (e.g., 'tags'), creating a mismatch.
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Verify default fallback behaviorExamine the policy configuration for the default rule (often shown as "default": "rule:admin_or_owner" or similar). Check if write operations on tags that do not match any explicit rule fall through to this default.Affected if The default rule allows the operation and tag write operations do not have explicit deny rules, causing fallback to permissive defaults.
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Test reader access to tag operationsIf feasible in a non-production environment, use a service user or token with only reader permissions (e.g., a role without write access) and attempt to create or update a tag on a resource within your project using the Neutron API.Affected if The tag creation or update operation succeeds despite the user lacking explicit write permissions, indicating the vulnerability is present.
You are affected if Neutron version is before 28.0.1 AND your policy configuration exhibits the singular/plural naming mismatch causing tag write operations to fall through to a permissive default rule.
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.
dbcve · scopedUpgrade to Neutron 28.0.1 or later to obtain the patch that aligns the policy action names, or apply the vendor-supplied patch that corrects the plural/singular naming mismatch in the policy enforcement logic.
OpenStack Neutron 28.0.1 or later
- 1. Upgrade OpenStack Neutron to version 28.0.1 or later
- 2. Verify the upgrade completed successfully by checking the Neutron version
- 3. Confirm the tagging controller now correctly enforces singular policy action names for single-tag write operations
- 4. Test that project readers can no longer create or update tags on same-project resources
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation3.0 h
- Testing4.0 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 $3,680.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-49299 — 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-2026-49299 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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