OctoPrint CVE-2026-35163
MEDIUM
GHSA-p6qx-ghxm-389h
Severity by source
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.
Lifecycle Timeline
2DescriptionCVE.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. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires that the 'Display notifications for suppressed commands' feature in OctoPrint's serial connection settings is active (the advisory's workaround specifically targets this setting, indicating it must be enabled for the popup to trigger). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | No CVSS vector or EPSS score is present in the available data, limiting quantitative risk comparison - severity metrics are therefore inferred from the description, CWE, and attack mechanics rather than confirmed by NVD or the vendor. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker crafts a G-code file embedding suppressed commands whose output contains a JavaScript payload (e.g., a fetch call exfiltrating document cookies or OctoPrint API keys to an attacker-controlled endpoint) and distributes it via a community print file repository, forum post, or direct message. A victim with OctoPrint administrator privileges downloads and prints the file; when the printer processes the suppressed command, OctoPrint renders the unsanitized notification popup in the victim's browser, executing the injected script. … |
| Remediation | 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. … Detailed patch versions, workarounds, and compensating controls in full report. |
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Same weakness CWE-80 – Basic XSS
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External POC / Exploit Code
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