OctoPrint has Timing Side-Channel Vulnerability in API Key AuthenticationGHSA-xg4x-w2j3-57h6
MEDIUMFix: OctoPrint/OctoPrint@249fd80GHSA-xg4x-w2j3-57h6 is a medium-severity (CVSS 5.9) CWE-208 vulnerability in octoprint. A fix is available for octoprint — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-xg4x-w2j3-57h6.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
octoprintReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | octoprint | all versions | 1.11.6pip install --upgrade 'octoprint==1.11.6' |
Affected Products
octoprintoctoprintDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for octoprint, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update octoprint to 1.11.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xg4x-w2j3-57h6 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is GHSA-xg4x-w2j3-57h6 in your dependencies?
Find it across PyPI, including transitive dependencies.