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CVE-2026-20155NVD status: Analyzed

Cisco Evolved Programmable Network Manager…: Missing Authorization

CVE-2026-20155 is a high-severity missing authorization vulnerability in Cisco Evolved Programmable Network Manager (EPNM) from Cisco, with a CVSS 3.1 base score of 8.0 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. Affected Cisco Evolved Programmable Network Manager (EPNM) versions: 7.1.1; 7.1.2.1; 7.1.3, 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 0.27% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Evolved Programmable Network Manager to 8.1.2 or a later version.
  2. Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco Evolved Programmable Network Manager (EPNM)7.1.1; 7.1.2.1; 7.1.3; 7.1.2; 7.1.0; 8.0.0; 8.0.0.1; 7.1.3.1; and 6 more rangesNot stated
CiscoEvolved Programmable Network Managerbefore 8.1.28.1.2

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
LowA basic user account is enough.
User interaction
RequiredA user must take an action such as opening a file or link.
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:L/UI:R/S:U/C:H/I:H/A:H. Scored by CNA (cisco.com).

Official description

A vulnerability in the web-based management interface of Cisco Evolved Programmable Network Manager (EPNM) could allow an authenticated, remote attacker with low privileges to access sensitive information that they are not authorized to access. This vulnerability is due to improper authorization checks on a REST API endpoint of an affected device. An attacker could exploit this vulnerability by querying the affected endpoint. A successful exploit could allow the attacker to view session information of active Cisco EPNM users, including users with administrative privileges, which could result in the affected device being compromised.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

How developers prevent this class of flaw

  • Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.

More Missing Authorization vulnerabilities (CWE-862)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Cisco Evolved Programmable Network Manager (EPNM)

All Cisco Evolved Programmable Network Manager (EPNM) vulnerabilities

Recent Missing Authorization vulnerabilities

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