CVE-2025-48879 is a medium-severity (CVSS 6.5) CWE-140 vulnerability in octoprint. A fix is available for octoprint — see the affected versions and patch details below.
OctoPrint Vulnerable to Denial of Service through malformed HTTP request
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 CVE-2025-48879.
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 until and including 1.11.1 contain a vulnerability that allows any unauthenticated attacker to send a manipulated broken multipart/form-data request to OctoPrint and through that make the web server component become unresponsive. This could be used to effectively run a denial of service attack on the OctoPrint server.
Patches
The vulnerability has been patched in version 1.11.2.
Workaround
OctoPrint administrators are once more reminded to not make OctoPrint available on hostile networks (e.g. the internet), regardless of whether this vulnerability is patched or not.
Details
The issue can be triggered by a broken multipart/form-data request lacking an end boundary to any of OctoPrint's endpoints implemented through the octoprint.server.util.tornado.UploadStorageFallbackHandler request handler. The request handler will get stuck in an endless busy loop, looking for a part of the request that will never come. As Tornado is single-threaded, that will effectively block the whole web server.
The fix adds detection of invalid requests like that and ensures they are handled gracefully with an HTTP 400 Bad Request response.
Credits
This vulnerability was discovered and responsibly disclosed to OctoPrint by Jacopo Tediosi.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | octoprint | all versions | 1.11.2pip install --upgrade 'octoprint==1.11.2' |
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 1.11.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-48879 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is CVE-2025-48879 in your dependencies?
Find it across PyPI, including transitive dependencies.