CVE-2026-22185
Description
A flaw was found in OpenLDAP Lightning Memory-Mapped Database (LMDB) mdb_load. When processing malformed input, a local attacker can exploit a heap buffer underflow vulnerability in the readline() function. This can lead to an out-of-bounds read, potentially causing a denial of service (DoS) and limited disclosure of heap memory contents.
Statement
This vulnerability is classified as Moderate rather than Important because its impact and exploitability are limited in scope and consequence. The flaw results in a one-byte heap out-of-bounds read caused by an integer underflow in mdb_load, which is a local, administrative utility rather than a long-running network-exposed service. Exploitation requires local execution and the ability to supply a malformed LMDB input file, significantly reducing the attack surface. While the issue can reliably trigger a process crash and may disclose minimal adjacent heap data, it does not allow memory corruption, privilege escalation, or arbitrary code execution. The confidentiality impact is low and bounded, and the availability impact is confined to the mdb_load invocation itself, not to the OpenLDAP daemon or directory service at runtime.
Mitigation
To reduce the risk from this vulnerability, administrators should avoid processing untrusted or externally supplied LMDB database files with mdb_load and restrict its use to trusted, local users only.
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 | 6.8 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | Low | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Instability
This weakness will generally lead to undefined behavior and therefore crashes. In the case of overflows involving loop index variables, the likelihood of infinite loops is also high.
Integrity
Technical Impact: Modify Memory
If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the wrap around results in other conditions such as buffer overflows, further memory corruption may occur.
Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism
This weakness can sometimes trigger buffer overflows which can be used to execute arbitrary code. This is usually outside the scope of a program's implicit security policy.
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