How severe is CVE-2020-5686?

CVE-2020-5686 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-5686 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-5686?

CVE-2020-5686 primarily affects Nec Univerge Sv9500 Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-5686?

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

When was CVE-2020-5686 published?

CVE-2020-5686 was published on 2021-01-13 and last updated on 2026-06-17.

CVE-2020-5686

CVE-2020-5686 is a high-severity vulnerability in Nec Univerge Sv9500 Firmware with a CVSS 3.x base score of 7.5. 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-287.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (63rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Nec Univerge Sv9500 Firmware
Published: 2021-01-13
Last modified: 2026-06-17

Description

Incorrect implementation of authentication algorithm issue in UNIVERGE SV9500 series from V1 to V7and SV8500 series from S6 to S8 allows an attacker to access the remote system maintenance feature and obtain the information by sending a specially crafted request to a specific URL.

Frequently asked questions

What is CVE-2020-5686?: Incorrect implementation of authentication algorithm issue in UNIVERGE SV9500 series from V1 to V7and SV8500 series from S6 to S8 allows an attacker to access the remote system maintenance feature and obtain the information by sending a specially crafted request to a specific URL.
How severe is CVE-2020-5686?: CVE-2020-5686 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-5686 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-5686?: CVE-2020-5686 primarily affects Nec Univerge Sv9500 Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-5686?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-5686 published?: CVE-2020-5686 was published on 2021-01-13 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:o:nec:univerge_sv9500_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:univerge_sv8500_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Nec Univerge Sv9500 Firmware

CVE-2020-5685 — Critical (CVSS 9.8): UNIVERGE SV9500 series from V1 to V7and SV8500 series from S6 to S8 allows an attacker to execute arbitrary OS commands…

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CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

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