# CVE-2026-20155: Cisco Evolved Programmable Network Manager Improper Authorization Vulnerability

> Authenticated low-privilege attackers can access sensitive session information via improper authorization checks, potentially leading to device compromise.

- **Severity:** High 8.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 1 Apr 2026
- **Updated:** 1 Apr 2026
- **Also known as:** GHSA-g5c4-x88j-p4hw

## What is CVE-2026-20155?

CVE-2026-20155 is a high-severity missing authorization vulnerability in Cisco Evolved Programmable Network Manager, published on 1 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### 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.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-20155?

It affects 1 product.


Products: Cisco Evolved Programmable Network Manager.

## How do I fix CVE-2026-20155?

No fix has been published for CVE-2026-20155 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-20155 being exploited?

There is no known exploitation of CVE-2026-20155 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Evolved Programmable Network Manager

- [CVE-2016-1289](https://insights.sbomify.com/CVE-2016-1289/): Code injection in n/a (critical 9.8)
- [CVE-2016-1291](https://insights.sbomify.com/CVE-2016-1291/): Deserialization in n/a (critical 9.8)
- [CVE-2021-1487](https://insights.sbomify.com/CVE-2021-1487/): Cisco Prime Infrastructure and Cisco Evolved Programmable Network Manager Command Injection Vulnerability (high 8.8)
- [CVE-2019-1821](https://insights.sbomify.com/CVE-2019-1821/): Cisco Prime Infrastructure and Evolved Programmable Network Manager Remote Code Execution Vulnerabilities (high 8.8)
- [CVE-2019-1822](https://insights.sbomify.com/CVE-2019-1822/): Cisco Prime Infrastructure and Evolved Programmable Network Manager Remote Code Execution Vulnerabilities (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20155 and fix it if it is affected.

What it is: CVE-2026-20155 is a high-severity missing authorization vulnerability in Cisco Evolved Programmable Network Manager, published on 1 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-20155 in the wild and no public exploit code.

Affected product: Cisco Evolved Programmable Network Manager. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-20155/ (Markdown: https://insights.sbomify.com/CVE-2026-20155/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20155
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20155
- OSV: https://osv.dev/vulnerability/CVE-2026-20155

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-20155/
Summaries are generated and may contain mistakes; the official description above is the record.