Is there a patch available for CVE-2026-35163?

Yes, a patch is available for CVE-2026-35163. Update the affected software to the latest version immediately.

OctoPrint CVE-2026-35163

Q: What is the CVSS score of CVE-2026-35163?

CVE-2026-35163 has a CVSS 4.0 base score of 4.6 (Medium). CVSS vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.1%.

EUVD-2026-64043 MEDIUM

Basic XSS (CWE-80)

2026-06-23 https://github.com/OctoPrint/OctoPrint

GHSA-p6qx-ghxm-389h PYSEC-2026-2688

XSS

4.6

CVSS 4.0 · Vendor: https://github.com/OctoPrint/OctoPrint

Severity by source

Vendor (https://github.com/OctoPrint/OctoPrint) PRIMARY

4.6 MEDIUM

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

7.1 HIGH

No attacker authentication required (PR:N); mandatory victim print action (UI:R); XSS crosses browser scope boundary (S:C); impact limited to partial C/I/A depending on victim permissions.

3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

4.0 AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N

Primary rating from Vendor (https://github.com/OctoPrint/OctoPrint).

CVSS VectorVendor: https://github.com/OctoPrint/OctoPrint

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Scope

Lifecycle Timeline

CVSS changed

Aug 21, 2026 - 19:22 NVD

4.6 (MEDIUM)

Source Code Evidence Fetched

Jun 23, 2026 - 17:37 vuln.today

Analysis Generated

Jun 23, 2026 - 17:37 vuln.today

DescriptionCVE.org

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.

Patches

The vulnerability has been patched in version 1.11.8 and 2.0.0rc3.

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

AnalysisAI

Stored XSS in OctoPrint's Suppressed Command Notifications feature enables injection of arbitrary HTML and JavaScript into browser popups triggered by specially crafted G-code print files. Versions up to and including 1.11.7 and pre-release builds 2.0.0rc1 and 2.0.0rc2 are affected. An attacker who successfully delivers a malicious G-code file to a victim can execute scripts in the victim's authenticated browser session, enabling exfiltration of sensitive OctoPrint configuration (including API keys and credentials for privileged users), unauthorized actions within the instance, or disruption of active print jobs. No public exploit has been identified at time of analysis, and the vulnerability was responsibly disclosed.

Technical ContextAI

OctoPrint is an open-source, web-based 3D printer management interface distributed as a Python pip package (pkg:pip/octoprint). The vulnerable component is the 'Suppressed Command Notifications' popup system, which displays in-browser alerts when the printer firmware issues commands that OctoPrint suppresses via its serial communication layer. CWE-80 (Improper Neutralization of Script-Related HTML Tags in a Web Page - Basic XSS) identifies the root cause: content derived from suppressed G-code commands is rendered into the DOM popup without adequate HTML encoding or sanitization. Because this content ultimately originates from attacker-controlled data embedded in a G-code file, the browser executes injected scripts in the context of the victim's authenticated OctoPrint session. Affected packages are pkg:pip/octoprint <= 1.11.7 and >= 2.0.0rc1, <= 2.0.0rc2.

RemediationAI

Upgrade OctoPrint to version 1.11.8 (stable branch) or 2.0.0rc3 (pre-release branch), both released 2026-06-23, via pip install --upgrade octoprint or pip install octoprint==1.11.8. These releases contain the vendor-confirmed patch for this XSS vulnerability. As an immediate workaround that fully eliminates the attack surface without patching, administrators should navigate to OctoPrint Settings → Serial Connection → Behaviour → Sanity Checking and set 'Display notifications for suppressed commands' to 'Never show notifications' - this disables the vulnerable popup component entirely with no impact on print functionality. Additionally, enforce a policy of only printing G-code files sourced from trusted origins, and prefer locally slicing files using a controlled application rather than accepting pre-sliced files from third parties. The full advisory and patch details are at https://github.com/OctoPrint/OctoPrint/security/advisories/GHSA-p6qx-ghxm-389h.