CVE-2026-19550
Description
A flaw was found in FreeIPA. The trust-fetch-domains command is gated by a read-only permission on the trust object rather than a trust-administration permission, allowing an authenticated, non-privileged IPA user to trigger a privileged Active Directory trust refresh using an attacker-supplied server and credentials, resulting in unauthorized, attacker-controlled modification of trusted-domain and ID-range identity data in the IPA LDAP directory.
Statement
This flaw only affects Identity Management (IdM/FreeIPA) servers where a cross-forest trust with Active Directory has been established (via ipa-adtrust-install and ipa trust-add). Servers without an active AD trust are not affected, since the trust object and the ADTRUST component required to reach the vulnerable code path do not exist in that configuration.
Exploitation requires an ordinary, non-administrative IdM user account to trigger the vulnerable trust-fetch-domains command against a server of the attacker's choosing — no delegated administrative privilege of any kind is required. On its own, this lets an authenticated non-admin user force the IdM server to launch a privileged helper process and initiate a network connection to attacker-controlled infrastructure.
Impersonating accounts in the trusted Active Directory domain — additionally requires the attacker to intercept and relay the resulting Kerberos authentication traffic, force a downgrade to the weaker encrypted-timestamp pre-authentication mechanism, and successfully recover the trust's interrealm secret through that downgrade.
Mitigation
This issue is fixed upstream. Administrators should apply this fix once available for their platform. Until then, the previously suggested compensating control (restricting "System: Read Trust Information" so it is not granted to all authenticated users) remains a valid interim workaround, with the same caveat that doing so may affect SSSD subdomain support, which relies on that permission's default breadth.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.2 | N/A | 8.2 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Changed | N/A | Changed |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
An attacker could bypass intended access restrictions to read sensitive data, either by reading the data directly from a data store that is not correctly restricted, or by accessing insufficiently-protected, privileged functionality to read the data.
Integrity
Technical Impact: Modify Application Data; Modify Files or Directories
An attacker could bypass intended access restrictions to modify sensitive data, either by writing the data directly to a data store that is not correctly restricted, or by accessing insufficiently-protected, privileged functionality to write the data.
Access Control
Technical Impact: Gain Privileges or Assume Identity; Bypass Protection Mechanism
An attacker could bypass intended access restrictions to gain privileges by modifying or reading critical data directly, or by accessing privileged functionality.
Confidentiality,Integrity,Availability
Technical Impact: Execute Unauthorized Code or Commands
An attacker could use elevated privileges to execute unauthorized commands or code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
An attacker could gain unauthorized access to resources on the system and excessively consume those resources, leading to a denial of service.
Acknowledgements
Red Hat would like to thank Andrew Rukin (Arenadata) for reporting this issue.
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