How severe is CVE-2026-120859?

No CVSS score has been assigned to CVE-2026-120859 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-120859?

Affected package information for CVE-2026-120859 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-120859?

Upgrade the affected component to the fixed release for CVE-2026-120859, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.

How do I detect CVE-2026-120859 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2026-120859 if there is no patch (or I can't update yet)?

Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Is CVE-2026-120859 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-120859 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-120859?

CVE-2026-120859 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 9th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-120859?

CVE-2026-120859 is classified as CWE-95 (CWE-95), Deserialization of Untrusted Data (CWE-502). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-120859 published, and has it been updated?

CVE-2026-120859 was published on November 5, 2026 and was last updated on November 5, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-120859: pymodaq RCE

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs9th percentile — riskier than 9% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Description

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.

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2026-120859, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

This vulnerability is rated as an Important severity flaw because an attacker who convinces a user to load a compromised file can execute arbitrary code with the user's privileges, though exploitation requires user interaction rather than occurring over a network without consent. PyMoDAQ and its related packages are…

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Source: Red Hat security advisory for CVE-2026-120859 (CC BY 4.0)

Frequently Asked Questions

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 fro

O3 Security · Impact-Aware SCA

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CVE-2026-120859 — pymodaq