OctoPrint has Timing Side-Channel Vulnerability in API Key Authentication
Impact
OctoPrint versions up to and including 1.11.5 are affected by a (theoretical) timing attack vulnerability that allows API key extraction over the network.
Due to using character based comparison that short-circuits on the first mismatched character during API key validation, rather than a cryptographical method with static runtime regardless of the point of mismatch, an attacker with network based access to an affected OctoPrint could extract API keys valid on the instance by measuring the response times of the denied access responses and guess an API key character by character.
Patches
The vulnerability will be patched in version 1.11.6.
Workaround
The likelihood of this attack actually working is highly dependent on the network's latency, noise and similar parameters. An actual proof of concept was not achieved so far. Still, as always administrators are advised to not expose their OctoPrint instance on hostile networks, especially not on the public Internet!
Credits
This vulnerability was discovered and responsibly disclosed to OctoPrint by Knox Liu.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | octoprint | < 1.11.6 | 1.11.6 |
References
- https://github.com/OctoPrint/OctoPrint/security/advisories/GHSA-xg4x-w2j3-57h6
- https://nvd.nist.gov/vuln/detail/CVE-2026-23892
- https://github.com/OctoPrint/OctoPrint/commit/249fd80ab01bc4b7dabedff768230a0fb5d01a8c
- https://github.com/OctoPrint/OctoPrint
- https://github.com/OctoPrint/OctoPrint/releases/tag/1.11.6
- https://pypi.org/project/octoprint
- https://github.com/advisories/GHSA-xg4x-w2j3-57h6
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N- Weakness (CWE)
CWE-208- Platform
- Python (PyPI)
- Package
octoprint- Disclosed
- 27.01.2026
- Updated
- 11.10.2026 13:19
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-1716 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-xg4x-w2j3-57h6 - 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.
- 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
- 2021: 2
- 2022: 8
- 2023: 1
- 2024: 5
- 2025: 5
- 2026: 3
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OctoPrint has Timing Side-Channel Vulnerability in API Key Authentication this entry
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