CVE-2026-35163 OctoPrint: XSS in Suppressed Command Notifications
Attackers can inject JavaScript into OctoPrint notifications via crafted print files, allowing session hijacking and data theft.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-35163?
CVE-2026-35163 is a medium-severity cross-site scripting vulnerability in OctoPrint, published on 21 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
OctoPrint provides a web interface for controlling consumer 3D printers. Prior to 1.11.8 and 2.0.0rc3, Suppressed Command notification popups use PNotify rendering for printer-controlled payload.command and payload.message values in src/octoprint/static/js/app/viewmodels/terminal.js without HTML escaping. An attacker who convinces a victim to print a crafted file can inject HTML and JavaScript into the notification, disrupt prints, read information available to the victim including sensitive settings when permitted, or perform actions in the victim's OctoPrint session. This issue is fixed in versions 1.11.8 and 2.0.0rc3.
Weakness: CWE-80
Which versions are affected by CVE-2026-35163?
5 open source packages ship an affected version, including octoprint and OctoPrint.
| Package | Affected | Fixed in |
|---|---|---|
octoprint PyPI | All versions | 1.11.8, 2.0.0rc3 |
octoprint PyPI | All versions | 1.11.8 |
octoprint PyPI | From 2.0.0rc1 | 2.0.0rc3 |
OctoPrint PyPI | All versions | 1.11.8 |
OctoPrint PyPI | From 2.0.0rc1 | 2.0.0rc3 |
How do I fix CVE-2026-35163?
Upgrade octoprint to a fixed version for your release line: 1.11.8 or 2.0.0rc3.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-35163 being exploited?
There is no known exploitation of CVE-2026-35163 in the wild and no public exploit code.
Sources
Also known as GHSA-p6qx-ghxm-389h, PYSEC-2026-2688.