How severe is CVE-2020-3526?

CVE-2020-3526 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-3526 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3526?

CVE-2020-3526 affects Cisco Ios Xe. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-3526?

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-2020-3526 published?

CVE-2020-3526 was published on 2020-09-24 and last updated on 2026-06-17.

CVE-2020-3526

CVE-2020-3526 is a high-severity vulnerability in Cisco Ios Xe with a CVSS 3.x base score of 8.6. 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-20.

Key facts

Severity: High (CVSS 3.x base score 8.6)
CVSS v2: 7.8
EPSS exploit prediction: 1% (69th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Cisco Ios Xe
Published: 2020-09-24
Last modified: 2026-06-17

Description

A vulnerability in the Common Open Policy Service (COPS) engine of Cisco IOS XE Software on Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, remote attacker to crash a device. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending a malformed COPS message to the device. A successful exploit could allow the attacker to crash the device.

Frequently asked questions

What is CVE-2020-3526?: A vulnerability in the Common Open Policy Service (COPS) engine of Cisco IOS XE Software on Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, remote attacker to crash a device. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending a malformed COPS message to the device. A successful exploit could allow the attacker to crash the device.
How severe is CVE-2020-3526?: CVE-2020-3526 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-3526 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3526?: CVE-2020-3526 affects Cisco Ios Xe. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-3526?: 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-2020-3526 published?: CVE-2020-3526 was published on 2020-09-24 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-COPS-VLD-MpbTvGEW

Affected products (1)

cpe:2.3:o:cisco:ios_xe:17.2:*:*:*:*:*:*:*

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