How severe is CVE-2020-3258?

CVE-2020-3258 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-2020-3258 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3258?

CVE-2020-3258 primarily affects Cisco Ios. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-3258?

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-2020-3258 published?

CVE-2020-3258 was published on 2020-06-03 and last updated on 2026-06-17.

CVE-2020-3258

CVE-2020-3258 is a critical-severity vulnerability in Cisco Ios 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-119.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Cisco Ios
Published: 2020-06-03
Last modified: 2026-06-17

Description

Multiple vulnerabilities in Cisco IOS Software for Cisco 809 and 829 Industrial Integrated Services Routers (Industrial ISRs) and Cisco 1000 Series Connected Grid Routers (CGR1000) could allow an unauthenticated, remote attacker or an authenticated, local attacker to execute arbitrary code on an affected system or cause an affected system to crash and reload. For more information about these vulnerabilities, see the Details section of this advisory.

Frequently asked questions

What is CVE-2020-3258?: Multiple vulnerabilities in Cisco IOS Software for Cisco 809 and 829 Industrial Integrated Services Routers (Industrial ISRs) and Cisco 1000 Series Connected Grid Routers (CGR1000) could allow an unauthenticated, remote attacker or an authenticated, local attacker to execute arbitrary code on an affected system or cause an affected system to crash and reload. For more information about these vulnerabilities, see the Details section of this advisory.
How severe is CVE-2020-3258?: CVE-2020-3258 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-2020-3258 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3258?: CVE-2020-3258 primarily affects Cisco Ios. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-3258?: 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-2020-3258 published?: CVE-2020-3258 was published on 2020-06-03 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-iot-rce-xYRSeMNH

Affected products (3)

cpe:2.3:o:cisco:ios:15.8\(3\)m2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.8\(9\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:15.9:*:*:*:*:*:*:*

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