CVE-2026-58222
Description
A security flaw combining LDAP filter injection and improper authorization checks was found in Samba Active Directory Domain Controller (AD DC). When processing LDAP Compare requests, Samba fails to properly validate user-supplied attribute names and executes the resulting internal database search in a trusted context, bypassing normal Access Control List (ACL) enforcement. An authenticated low-privilege domain user can exploit these flaws to disclose confidential Active Directory attributes that would normally be inaccessible. The disclosed information may be leveraged to derive sensitive authentication material, potentially leading to privilege escalation and complete domain compromise. For example: In deployments configured with Group Managed Service Accounts (gMSAs), an attacker can extract the "msKds-RootKeyData" attribute and derive gMSA passwords offline, potentially leading to complete domain compromise if privileged gMSAs are present.
Statement
Red Hat Product Security has rated this vulnerability as having an Important security impact for Samba deployments operating as an Active Directory Domain Controller (AD DC)
Red Hat Enterprise Linux (RHEL) context: Standard installations of Red Hat Enterprise Linux (RHEL) are not affected. RHEL packages Samba strictly to operate as a file server (smbd), print server, or Active Directory domain member (winbindd). RHEL does not ship or support the Samba Active Directory Domain Controller (AD DC) role where this LDAP Compare request flaw exists.
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 | 8.8 | N/A | 8.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability
Technical Impact: Execute Unauthorized Code or Commands; Read Application Data; Modify Application Data
An attacker could include input that changes the LDAP query which allows unintended commands or code to be executed, allows sensitive data to be read or modified or causes other unintended behavior.
Acknowledgements
Red Hat would like to thank Andrew Tridgell (Samba Team), Bin Luo (University of Electronic Science and Technology of China (UESTC)), OpenAI Security Research, and Tristan Madani (Talence Security) for reporting this issue.
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