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Full vulnerability report · 2026
CVE-2026-20321High confidence

Cisco Application Policy Infrastructure Controller API Command Injection Vulnerability

Cisco · Cisco Application Policy Infrastructure Controller (APIC)

Official source article: Cisco CISCO-SA-APIC-CMDINJ-L6VR4E7 ↗. Check the applicable product and release in the original source.

6.5MediumCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 11 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.43% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Cisco Cisco Application Policy Infrastructure Controller (APIC) and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 11 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
cisco-sa-apic-cmdinj-L6VR4E7 · CSAF 2.0 · revision 1.0.0 · finalCisco PSIRTCisco Application Policy Infrastructure Controller API Command Injection Vulnerability
11 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • CSAFPID-202553
  • 5.3(1d)
  • 5.3(2a)
  • 5.3(2b)
  • 5.3(2c)
  • 5.3(2d)
  • 5.3(2e)
  • 5.3(2f)
  • 6.1(5e)
  • 6.2(1g)
  • 6.2(2e)
Summary
Complete.
Remediation
Cisco has released software updates that address this vulnerability.
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-94524

No EUVD known-exploited evidence

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.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
6.5 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 11 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

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.

What

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.

Why

The product does not use a standardized method for handling errors throughout the code, which might introduce inconsistent error handling and resultant weaknesses.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may execute code or commands in the affected security context.

What

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.

Why

The product does not use a standardized method for handling errors throughout the code, which might introduce inconsistent error handling and resultant weaknesses.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may execute code or commands in the affected security context.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Missing Standardized Error Handling Mechanism → execute code or commands in the affected security context
Attack surface
Network
Privileges required
High: elevated access is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-544 ↗

CWE-544: Missing Standardized Error Handling Mechanism. The product does not use a standardized method for handling errors throughout the code, which might introduce inconsistent error handling and resultant weaknesses.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
NetworkRemote code executionCWE-544
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-94524Official EUVD mapping

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.

Official EUVD record ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix availability varies by product
Affected
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 7 Oct 2026 · Last source change 8 Oct 2026, 15:33 UTC · CWE-544 · Missing Standardized Error Handling Mechanism

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-10-08
European sourceENISA EUVD · EUVD-2026-94524
Product sourceVendor CSAF · Cisco PSIRT
Remediation sourceVendor CSAF · Cisco PSIRT
CWE sourceCNA
NVD statusNVD awaiting enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Vendor guidanceAuthoritative vendor guidance changed: removed patch: sec.cloudapps.cisco.com/cisco-sa-apic-cmdinj-L6VR4E7; removed remediation: sec.cloudapps.cisco.com/cisco-sa-apic-cmdinj-L6VR4E7.
    Before
    patch: sec.cloudapps.cisco.com/cisco-sa-apic-cmdinj-L6VR4E7 · remediation: sec.cloudapps.cisco.com/cisco-sa-apic-cmdinj-L6VR4E7
    After
    no authoritative guidance recorded
    CNA ↗
  2. Remediation statusRemediation status changed from Mitigation available to Awaiting fix.
    Before
    Mitigation available
    After
    Awaiting fix
    CNA ↗
  3. ENISA EUVD mappingEUVD-2026-94524 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-94524"}
    ENISA EUVD ↗
  4. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
  5. Remediation statusRemediation status changed from Awaiting fix to Mitigation available.
    Before
    Awaiting fix
    After
    Mitigation available
    Cisco PSIRT ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-20321 · cve.blacktree.nl