CVE-2026-20321

Medium [CVE-2026-20321] Cisco Application Policy Infrastructure Controller API Command Injection Vulnerability

cisco-sa-apic-cmdinj-L6VR4E7Source published Oct 7, 2026Source updated Oct 7, 2026

A vulnerability in the web-based management API for Cisco Application Policy Infrastructure Controller (APIC) could allow an authenticated, remote attacker to execute arbitrary commands as the root user. To exploit this vulnerability, the attacker must have valid administrative credentials. This vulnerability is due to insufficient input validation of user-controlled command arguments. An attacker could exploit this vulnerability by authenticating using the API and sending crafted input. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system of an affected device with root-level privileges. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is…

Affected products in this advisory

• Application Policy Infrastructure Controller (APIC)

Source-reported affected versions

• Scope: At the time of publication, this vulnerability affected Cisco APIC, regardless of device configuration.
• 5.3 and earlier — Migrate to a fixed release
• Release 6.0 (first fixed: 6.0(9h))
• Release 6.1 (first fixed: 6.1(6g))

1 more entries in the full advisory.

Source-reported fixed versions

• 6.0(9h)
• 6.1(6g)
• 6.2(3g)

Mitigation guidance

• Upgrade to the first fixed release for your train per the Fixed Releases table in this advisory.
• Release 5.3 and earlier: migrate to a fixed release.
• Release 6.0: upgrade to 6.0(9h).
• Release 6.1: upgrade to 6.1(6g).

1 more entries in the full advisory.

Workarounds

• There are no workarounds that address this vulnerability.