Medium

OctoPrint Authenticated Reverse Proxy Page Authentication Bypass

  • Disclosed: 22.04.2025
  • Updated: 11.10.2026 12:19

Impact

OctoPrint versions up until and including 1.10.3 contain a vulnerability that allows an attacker to bypass the login redirect and directly access the rendered HTML of certain frontend pages.

The impact on data exposure is minimal because, typically, data is loaded via API requests that correctly enforce user authentication. In the current codebase, cases where data is directly embedded in the page content are rare. However, one notable exception is the authenticated variant of the reverse proxy test page, which displays the IP addresses of configured reverse proxies.

The primary risk lies in potential future modifications to the codebase that might incorrectly rely on the vulnerable internal functions for authentication checks, leading to security vulnerabilities.

Patches

The vulnerability has been patched in version 1.11.0.

Details

An authentication bypass vulnerability exists in the following functions defined in octoprint/server/util/init.py:

  • require_login
  • require_login_with
  • require_fresh_login_with

By adding the HTTP header X-Preemptive-Recording: yes to HTTP requests, these functions allow requests to proceed without redirecting to the login screen, effectively bypassing the login mechanism in the frontend. However, this only grants access to frontend page content, while authenticated API endpoints still enforce proper session validation.

Credits

This vulnerability was discovered and responsibly disclosed to OctoPrint by Jacopo Tediosi

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Python (PyPI) octoprint < 1.11.0 1.11.0

References

CVSS score 4.3/10
CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Weakness (CWE)
CWE-290
Platform
Python (PyPI)
Package
octoprint
Disclosed
22.04.2025
Updated
11.10.2026 12:19

Sources and licenses

OSV / GitHub Advisory Database - PYSEC-2025-56 - PyPA Advisory Database; CC BY 4.0

OSV / GitHub Advisory Database - GHSA-qw93-h6pf-226x - CC BY 4.0

Vulnerability history: octoprint

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (24) in the archive
Total entries
24
First → latest
05.2021 06.2026
Without a fix
1
Exploited in attacks
0

Severity breakdown

  • Critical 1
  • High 8
  • Medium 13
  • Low 2

Disclosures per year

  1. 2021: 2
  2. 2022: 8
  3. 2023: 1
  4. 2024: 5
  5. 2025: 5
  6. 2026: 3
Severity:
  1. High CVE-2026-54134 < 1.11.8, >= 2.0.0rc1, < 2.0.0rc3 1.11.8, 2.0.0rc3
  2. OctoPrint Authenticated Reverse Proxy Page Authentication Bypass this entry
    Medium · 4.3 CVE-2025-32788 < 1.11.0 1.11.0
  3. High · 7.5 CVE-2022-1432 < 1.8.0 1.8.0
  4. High · 7.5 CVE-2022-1430 < 1.8.0 1.8.0

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