Summary
Workaround
OctoPrint administrators can mitigate the risk by disabling popups:
- for Action Command notifications, set OctoPrint Settings -> Serial Connection -> Behaviour -> Sanity Checking -> Display notifications for suppressed commands to Never show notifications
It is also strongly recommended to ensure that files being printed originate from trusted sources, and, whenever possible, are sliced with an application's own slicer.
Credits
This vulnerability was discovered and responsibly disclosed to OctoPrint by Jacopo Tediosi.
Timeline
2026-03-18: Report received
2026-04-01: Report verified
2026-04-01: Fix ready for 2.0.0
2026-06-22: Fix backported to 1.11.x
2026-06-23: Fix released with 1.11.8 and 2.0.0rc3
Impact
OctoPrint versions up to and including 1.11.7 as well as 2.0.0rc1 and 2.0.0rc2 are affected by a vulnerability that allows injection of arbitrary HTML and JavaScript into Suppressed Command notifications popups generated by the printer.
An attacker who successfully convinces a victim to print a specially crafted file could exploit this issue to disrupt ongoing prints, extract information (including sensitive configuration settings, if the targeted user has the necessary permissions for that), or perform other actions on behalf of the targeted user within the OctoPrint instance.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
The vulnerability has been patched in version 1.11.8 and 2.0.0rc3.
Frequently Asked Questions
- What is CVE-2026-35163? CVE-2026-35163 is a medium-severity security vulnerability in OctoPrint (pip), affecting versions <= 1.11.7. It is fixed in 1.11.8, 2.0.0rc3.
- Which versions of OctoPrint are affected by CVE-2026-35163? OctoPrint (pip) versions <= 1.11.7 is affected.
- Is there a fix for CVE-2026-35163? Yes. CVE-2026-35163 is fixed in 1.11.8, 2.0.0rc3. Upgrade to this version or later.
- Is CVE-2026-35163 exploitable, and should I be worried? Whether CVE-2026-35163 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-35163 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-35163?
- Upgrade
OctoPrintto 1.11.8 or later - Upgrade
OctoPrintto 2.0.0rc3 or later
- Upgrade