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

Status: published. Published: 2026-11-09. Updated: 2026-11-14.

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.

## Remediation

- fix: OctoPrint (pip): GitHub reports patched versions 2.0.0rc7. Check the advisory for the affected release branch. (source: GitHub GHSA-p623-mxf7-qxjm) — https://github.com/OctoPrint/OctoPrint/security/advisories/GHSA-p623-mxf7-qxjm
- fix: octoprint (PyPI): OSV reports a fixed version 2.0.0rc7. Check the advisory for supported release branches. (source: OSV GHSA-p623-mxf7-qxjm) — https://github.com/advisories/GHSA-p623-mxf7-qxjm

## Affected products and versions

- OctoPrint / OctoPrint: >= 2.0.0rc1, < 2.0.0rc7 (affected). Source: CNA: GitHub_M
-  / OctoPrint (OctoPrint): >= 2.0.0rc1, <= 2.0.0rc6 (affected, GitHub advisory range). Source: GitHub GHSA-p623-mxf7-qxjm
-  / octoprint (octoprint): 2.0.0rc1 (affected, PyPI); 2.0.0rc2 (affected, PyPI); 2.0.0rc3 (affected, PyPI); 2.0.0rc4 (affected, PyPI); 2.0.0rc5 (affected, PyPI); 2.0.0rc6 (affected, PyPI); Ecosystem version events: introduced 2.0.0rc1; fixed 2.0.0rc7. Source: OSV GHSA-p623-mxf7-qxjm

## Severity and prioritization

- CVSS 4.0: 2.4 (low); 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; source: CNA: GitHub_M

- CVSS 4.0: 2.4 (low); 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: 0.25% as of 2026-11-13; percentile 16.09%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-79

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/OctoPrint/OctoPrint/security/advisories/GHSA-p623-mxf7-qxjm (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/OctoPrint/OctoPrint/commit/059495787a1086868a28ba9eca8d089729242646 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/OctoPrint/OctoPrint/releases/tag/2.0.0rc7 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/OctoPrint/OctoPrint/commit/059495787a1086868a28ba9eca8d089729242646 (security-advisories@github.com)

- https://github.com/OctoPrint/OctoPrint/releases/tag/2.0.0rc7 (security-advisories@github.com)

- https://github.com/OctoPrint/OctoPrint/security/advisories/GHSA-p623-mxf7-qxjm (security-advisories@github.com)

- https://github.com/OctoPrint/OctoPrint/security/advisories/GHSA-p623-mxf7-qxjm (GitHub Security Advisories; advisory)

- https://github.com/advisories/GHSA-p623-mxf7-qxjm (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-p623-mxf7-qxjm (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-123364; retrieved 2026-11-14; source updated 2026-11-14

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123364; retrieved 2026-11-09; source updated 2026-11-09

- GitHub Security Advisories: https://github.com/OctoPrint/OctoPrint/security/advisories/GHSA-p623-mxf7-qxjm; retrieved 2026-11-12; source updated 2026-11-09

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-p623-mxf7-qxjm; retrieved 2026-11-14; source updated 2026-11-10

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-123364; retrieved 2026-11-14; source updated Not reported

Revision: cb0bca9d295243555ead6f247606b0db36535e29c92d19158e6dd47e965c3e0d

Canonical: https://y2.dev/cve/CVE-2026-123364

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