CVE-2026-11785
Description
A flaw was found in 389 Directory Server. A type confusion in the SSO token extended operation handler causes partial stack address information to be disclosed in LDAP responses to authenticated users.
Statement
This Moderate impact flaw in 389 Directory Server allows an authenticated, non-administrator user to obtain partial stack address information. The SSO token feature, which is enabled by default in Red Hat Directory Server, leaks the lower 32 bits of a stack address in LDAP extended operation responses, reducing Address Space Layout Randomization (ASLR) entropy but not leading to a full bypass.
Mitigation
Option 1 (Recommended): Disable the SSO token feature entirely: dsconf <instance> config replace nsslapd-enable-ldapssotoken=off. This prevents the vulnerable code path from being reached but disables SSO token functionality for all users. Option 2: Restrict network access to LDAP ports (389/636) to trusted networks via firewall rules. Note: Removing the SSO token secret from configuration does not mitigate the vulnerability — the server auto-generates a new secret at startup.
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 | 4.3 | N/A | 4.3 |
| 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 | Low | N/A | Low |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Red Hat CVSS v3 Score Explanation
C:L — partial stack address (low 32 bits only), not full ASLR bypass. PR:L — any authenticated user. SSO token enabled by default.
Understanding the Weakness (CWE)
Availability,Integrity,Confidentiality
Technical Impact: Read Memory; Modify Memory; Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart
When a memory buffer is accessed using the wrong type, it could read or write memory out of the bounds of the buffer, if the allocated buffer is smaller than the type that the code is attempting to access, leading to a crash and possibly code execution.
Acknowledgements
This issue was discovered by Ian Murphy (Red Hat).
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