How severe is CVE-2020-6959?

CVE-2020-6959 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-6959 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-6959?

CVE-2020-6959 primarily affects Honeywell Maxpro Nvr Xe Firmware. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-6959?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2020-6959 published?

CVE-2020-6959 was published on 2020-01-22 and last updated on 2026-06-17.

CVE-2020-6959

CVE-2020-6959 is a critical-severity vulnerability in Honeywell Maxpro Nvr Xe Firmware with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (80th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Affected product: Honeywell Maxpro Nvr Xe Firmware
Published: 2020-01-22
Last modified: 2026-06-17

Description

The following versions of MAXPRO VMS and NVR, MAXPRO VMS:HNMSWVMS prior to Version VMS560 Build 595 T2-Patch, HNMSWVMSLT prior to Version VMS560 Build 595 T2-Patch, MAXPRO NVR: MAXPRO NVR XE prior to Version NVR 5.6 Build 595 T2-Patch, MAXPRO NVR SE prior to Version NVR 5.6 Build 595 T2-Patch, MAXPRO NVR PE prior to Version NVR 5.6 Build 595 T2-Patch, and MPNVRSWXX prior to Version NVR 5.6 Build 595 T2-Patch are vulnerable to an unsafe deserialization of untrusted data. An attacker may be able to remotely modify deserialized data without authentication using a specially crafted web request, resulting in remote code execution.

Frequently asked questions

What is CVE-2020-6959?: The following versions of MAXPRO VMS and NVR, MAXPRO VMS:HNMSWVMS prior to Version VMS560 Build 595 T2-Patch, HNMSWVMSLT prior to Version VMS560 Build 595 T2-Patch, MAXPRO NVR: MAXPRO NVR XE prior to Version NVR 5.6 Build 595 T2-Patch, MAXPRO NVR SE prior to Version NVR 5.6 Build 595 T2-Patch, MAXPRO NVR PE prior to Version NVR 5.6 Build 595 T2-Patch, and MPNVRSWXX prior to Version NVR 5.6 Build 595 T2-Patch are vulnerable to an unsafe deserialization of untrusted data. An attacker may be able to remotely modify deserialized data without authentication using a specially crafted web request, resulting in remote code execution.
How severe is CVE-2020-6959?: CVE-2020-6959 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-6959 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-6959?: CVE-2020-6959 primarily affects Honeywell Maxpro Nvr Xe Firmware. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-6959?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-6959 published?: CVE-2020-6959 was published on 2020-01-22 and last updated on 2026-06-17.

References

https://www.us-cert.gov/ics/advisories/icsa-20-021-01

Affected products (6)

cpe:2.3:o:honeywell:maxpro_nvr_xe_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:honeywell:maxpro_nvr_se_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:honeywell:maxpro_nvr_pe_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:honeywell:mpnvrswxx_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:honeywell:hnmswvms_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:honeywell:hnmswvmslt_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Honeywell Maxpro Nvr Xe Firmware

CVE-2020-6960 — Critical (CVSS 9.8): The following versions of MAXPRO VMS and NVR, MAXPRO VMS:HNMSWVMS prior to Version VMS560 Build 595 T2-Patch,…
CVE-2017-14263 — High (CVSS 8.1): Honeywell NVR devices allow remote attackers to create a user account in the admin group by leveraging access to a…

All CVEs affecting Honeywell Maxpro Nvr Xe Firmware →

Other CWE-502 (Deserialization of Untrusted Data) vulnerabilities

CVE-2026-41104 — Critical (CVSS 10.0): Deserialization of untrusted data in Microsoft Planetary Computer Pro allows an unauthorized attacker to disclose…
CVE-2026-43633 — Critical (CVSS 10.0): HestiaCP versions 1.9.0 through 1.9.4 contain a deserialization vulnerability in the web terminal component caused by a…
CVE-2026-33819 — Critical (CVSS 10.0): Deserialization of untrusted data in Microsoft Bing allows an unauthorized attacker to execute code over a network.
CVE-2026-20131 — Critical (CVSS 10.0): A vulnerability in the web-based management interface of Cisco Secure Firewall Management Center (FMC) Software could…
CVE-2026-25632 — Critical (CVSS 10.0): EPyT-Flow is a Python package designed for the easy generation of hydraulic and water quality scenario data of water…
CVE-2025-14931 — Critical (CVSS 10.0): Hugging Face smolagents Remote Python Executor Deserialization of Untrusted Data Remote Code Execution Vulnerability.…

Browse all CWE-502 (Deserialization of Untrusted Data) vulnerabilities →