# CVE-2026-11861: Freeipa: idm: ipa: freeipa: obtaining tgs with impersonating cname through trust relationships

> Authenticated Active Directory users can bypass authentication and escalate privileges in FreeIPA by impersonating client names due to missing PAC verification.

- **Severity:** Critical 9.6 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Aug 2026
- **Updated:** 26 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-11861, GHSA-g67c-jg9c-rqh2, UBUNTU-CVE-2026-11861

## What is CVE-2026-11861?

CVE-2026-11861 is a critical authentication bypass vulnerability in Redhat Enterprise Linux, published on 20 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A flaw was found in FreeIPA. When a trust relationship is configured between FreeIPA and Active Directory, Active Directory users can bypass authentication for FreeIPA services, including the portal, SMB server, and LDAP directory. This is possible by impersonating a client name in the Ticket Granting Service (TGS) due to FreeIPA services not verifying Privilege Attribute Certificate (PAC) certificates. This vulnerability could allow an authenticated Active Directory user to escalate their privileges within the FreeIPA domain.

Weakness: CWE-266 (Incorrect Privilege Assignment)

## Which versions are affected by CVE-2026-11861?

It affects 2 products.


Products: Freeipa Freeipa, Redhat Enterprise Linux.

## How do I fix CVE-2026-11861?

Apply the vendor's patch.

## Is CVE-2026-11861 being exploited?

There is no known exploitation of CVE-2026-11861 in the wild and no public exploit code.

## Other vulnerabilities in Redhat Enterprise Linux

- [CVE-2015-5284](https://insights.sbomify.com/CVE-2015-5284/): Information disclosure in n/a (critical 9.8)
- [CVE-2024-2698](https://insights.sbomify.com/CVE-2024-2698/): Freeipa: delegation rules allow a proxy service to impersonate any user to access another target service (high 8.8)
- [CVE-2012-5631](https://insights.sbomify.com/CVE-2012-5631/): Information disclosure in ipa (high 8.8)
- [CVE-2017-11191](https://insights.sbomify.com/CVE-2017-11191/): Security feature bypass in n/a (high 8.8)
- [CVE-2026-13097](https://insights.sbomify.com/CVE-2026-13097/): Privilege escalation in Red Hat Enterprise Linux 10 (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-11861 and fix it if it is affected.

What it is: CVE-2026-11861 is a critical authentication bypass vulnerability in Redhat Enterprise Linux, published on 20 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-11861 in the wild and no public exploit code.

Affected product: Redhat Enterprise Linux. 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-2026-11861/ (Markdown: https://insights.sbomify.com/CVE-2026-11861/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-11861
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11861
- OSV: https://osv.dev/vulnerability/CVE-2026-11861

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-11861/
Summaries are generated and may contain mistakes; the official description above is the record.