Device reload via invalid Ethernet frame length
Published Feb 25, 2026 · Updated Feb 25, 2026
Denial of service in Cisco NX-OS in ACI Mode allows adjacent attackers to reload affected switches via crafted Ethernet frames. The OOB management interface processes an attacker-controlled frame with insufficient length validation, causing out-of-bounds buffer access and an unexpected device reload. Exploitation requires no authentication but requires Layer 2 adjacency to a configured and active OOB management interface; the reported consequence is a reboot and service interruption.
Summary
What happened
Denial of service in Cisco NX-OS in ACI Mode allows adjacent attackers to reload affected switches via crafted Ethernet frames. The OOB management interface processes an attacker-controlled frame with insufficient length validation, causing out-of-bounds buffer access and an unexpected device reload. Exploitation requires no authentication but requires Layer 2 adjacency to a configured and active OOB management interface; the reported consequence is a reboot and service interruption.
The record
- CVE
- CVE-2026-20033
- Published
- Feb 25, 2026
- Updated
- Feb 25, 2026
- Vendor
- ClamAV
- Product
- Cisco NX-OS in ACI Mode
- Classifications
- CWE-805, T1499
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 25, 2026CVE publishedPublication date reported by the CVE source.
- Feb 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=15.2(1g)
- Affected versionversion=15.2(2e)
- Affected versionversion=15.2(2f)
- Affected versionversion=15.2(2g)
- Affected versionversion=15.2(2h)
- Affected versionversion=15.2(3e)
- Affected versionversion=15.2(3f)
- Affected versionversion=15.2(3g)
- Affected versionversion=15.2(4d)
- Affected versionversion=15.2(4e)
- Affected versionversion=15.2(4f)
- Affected versionversion=15.2(5c)
- Affected versionversion=15.2(5d)
- Affected versionversion=15.2(5e)
- Affected versionversion=15.2(6e)
- Affected versionversion=15.2(6g)
- Affected versionversion=15.2(6h)
- Affected versionversion=15.2(7f)
- Affected versionversion=15.2(7g)
- Affected versionversion=15.2(8d)
- Affected versionversion=15.2(8e)
- Affected versionversion=15.2(8f)
- Affected versionversion=15.2(8g)
- Affected versionversion=15.2(8h)
- Affected versionversion=15.2(8i)
- Affected versionversion=15.3(1d)
- Affected versionversion=15.3(2a)
- Affected versionversion=15.3(2b)
- Affected versionversion=15.3(2c)
- Affected versionversion=15.3(2d)
- Affected versionversion=15.3(2e)
- Affected versionversion=15.3(2f)
- Affected versionversion=16.0(1g)
- Affected versionversion=16.0(1j)
- Affected versionversion=16.0(2h)
- Affected versionversion=16.0(2j)
- Affected versionversion=16.0(3d)
- Affected versionversion=16.0(3e)
- Affected versionversion=16.0(3g)
- Affected versionversion=16.0(4c)
- Affected versionversion=16.0(5h)
- Affected versionversion=16.0(5j)
- Affected versionversion=16.0(6c)
- Affected versionversion=16.0(6h)
- Affected versionversion=16.0(7e)
- Affected versionversion=16.0(8e)
- Affected versionversion=16.0(8f)
- Affected versionversion=16.0(8h)
- Affected versionversion=16.0(9c)
- Affected versionversion=16.0(9d)
- Affected versionversion=16.0(9e)
- Affected versionversion=16.1(1f)
- Affected versionversion=16.1(2f)
- Affected versionversion=16.1(2g)
- Affected versionversion=16.1(3f)
- Affected versionversion=16.1(3g)
- Affected versionversion=16.1(4h)
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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