# CVE-2026-20029: Cisco Identity Services Engine XML External Entity Processing Information Disclosure Vulnerability

> An authenticated administrator can exploit an XML parsing flaw in Cisco ISE to read arbitrary files from the underlying operating system.

- **Severity:** Medium 4.9 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Jan 2026
- **Updated:** 7 Jan 2026
- **Also known as:** GHSA-f26c-v5jj-mj89

## What is CVE-2026-20029?

CVE-2026-20029 is a medium-severity vulnerability in Cisco Identity Services Engine Software, published on 7 Jan 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A vulnerability in the licensing features of Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC) could allow an authenticated, remote attacker with administrative privileges to gain access to sensitive information. 

This vulnerability is due to improper parsing of XML that is processed by the web-based management interface of Cisco ISE and Cisco ISE-PIC. An attacker could exploit this vulnerability by uploading a malicious file to the application. A successful exploit could allow the attacker to read arbitrary files from the underlying operating system that could include sensitive data that should otherwise be inaccessible even to administrators. To exploit this vulnerability, the attacker must have valid administrative credentials.

Weakness: CWE-611 (Improper Restriction of XML External Entity Reference)

## Which versions are affected by CVE-2026-20029?


## How do I fix CVE-2026-20029?

No fix has been published for CVE-2026-20029 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-20029 being exploited?

There is no known exploitation of CVE-2026-20029 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20029 and fix it if it is affected.

What it is: CVE-2026-20029 is a medium-severity vulnerability in Cisco Identity Services Engine Software, published on 7 Jan 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-20029 in the wild and no public exploit code.

Affected product: Cisco Identity Services Engine Software. 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-2026-20029/ (Markdown: https://insights.sbomify.com/CVE-2026-20029/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20029
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20029
- OSV: https://osv.dev/vulnerability/CVE-2026-20029

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-20029/
Summaries are generated and may contain mistakes; the official description above is the record.