Sources: National Vulnerability Database, CVE.org, CISA KEV, FIRST EPSS
CVE-2026-120859 Overview
PyMoDAQ before 4.4.13, and pymodaq_data, pymodaq_gui, and pymodaq_utils before 5.1.15, 5.2.x before 5.2.14, and 5.3.x before 5.3.10, contain deserialization of untrusted data and eval injection vulnerabilities that allow attackers to execute arbitrary code by supplying crafted files that a user opens. Attackers can store pickled objects in HDF5 string nodes that StringARRAY.array_to_string() passes to pickle.loads() when the node is browsed or read, place Python expressions in HDF5 attributes that JsonConverter.json2object() evaluates, supply a .dock file that load_layout_state() unpickles from the Dashboard Load layout action, or embed Python expressions in XML settings files that elt_to_dict() and set_txt_from_elt() evaluate.
Critical Impact
Affected Products
- PyMoDAQ: see the vendor advisory for the exact affected versions
Discovery Timeline
- 2026-11-05: CVE-2026-120859 published to the National Vulnerability Database by disclosure@vulncheck.com
- 2026-11-05: last updated in the NVD database
Technical Details for CVE-2026-120859
Vulnerability Analysis
CVE-2026-120859 is a Deserialization of Untrusted Data weakness (CWE-95, CWE-502: Deserialization of Untrusted Data) in PyMoDAQ. Based on its CVSS vector, the flaw needs local or adjacent access, needs no login, and relies on a user taking an action. The application rebuilds objects from attacker controlled data, which can run code.
With a CVSS base score of 8.5, apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Root Cause
The weakness is classified as CWE-95, CWE-502: Deserialization of Untrusted Data. The application rebuilds objects from attacker controlled data, which can run code.
Attack Vector
Based on the CVSS vector, the flaw needs local or adjacent access, needs no login, and relies on a user taking an action. Attack complexity is low complexity.
No exploitation in the wild is confirmed by CISA at the time of the last update. Check the references below for any vendor or researcher proof of concept.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/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
Detection Methods for CVE-2026-120859
Detection Strategies
- Inventory every instance of PyMoDAQ and compare the running version with the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Run an authenticated vulnerability scan once your scanner ships a check for this CVE.
Monitoring Recommendations
- Forward PyMoDAQ application, access and audit logs to your SIEM for retrospective hunting.
- Alert on new processes, configuration changes or outbound connections from the affected service.
- Track the vendor advisory and the CISA KEV catalog for changes in exploitation status.
How to Mitigate CVE-2026-120859
Immediate Actions Required
- Apply the fixed version of PyMoDAQ named in the vendor advisory.
- Prioritize internet facing and business critical instances first.
- Rescan after the change to confirm the exposure is closed.
Patch Information
Use the fixed version listed in the vendor advisory for PyMoDAQ.
Workarounds
- If patching must wait, restrict network access to the affected service and place it behind authentication or a web application firewall rule.
CWE References
- CWE-95 More CVEs with this weakness
- CWE-502: Deserialization of Untrusted Data More CVEs with this weakness
Technical References
- ▸NVD entry
- ▸CVE.org record
- ▸GitHub repository reference
- ▸Fix commit on GitHub
- ▸Fix commit on GitHub
- ▸Fix commit on GitHub
- ▸Fix commit on GitHub
- ▸GitHub repository reference
- ▸GitHub repository reference
- ▸GitHub repository reference
- ▸GitHub repository reference
- ▸GitHub Security Advisory
- ▸Advisory on vulncheck.com
This entry is built directly from NVD, CISA KEV and EPSS data. Verify fixed versions in the vendor advisory before you deploy.
Frequently asked questions
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