Cisco Application Policy Infrastructure…: Improper Neutralization
CVE-2026-76499 is a critical-severity improper neutralization vulnerability in Cisco Application Policy Infrastructure Controller (APIC) from Cisco, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Cisco Application Policy Infrastructure Controller (APIC) versions: 5.2(1g); 5.2(2e); 5.2(2f), and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.33% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Cisco Application Policy Infrastructure Controller (APIC) you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco Application Policy Infrastructure Controller (APIC) | 5.2(1g); 5.2(2e); 5.2(2f); 5.2(2g); 5.2(2h); 5.2(3f); 5.2(3e); 5.2(3g); and 32 more ranges | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cisco.com).
Official description
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Application Policy Infrastructure Controller (APIC) engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-76499 are related to improper neutralization issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-707.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization
The product does not ensure or incorrectly ensures that structured messages or data are well-formed and that certain security properties are met before being used when received from an upstream component, or before being sent to a downstream component.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Cisco Application Policy Infrastructure Controller (APIC)
- 9.8 Critical severity
- 9.8 Critical severity
- 7.2 High severity
- 8.8 High severity
Recent Improper Neutralization vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 9.9 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 8.6 High severity
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