CVE-2026-42440
Description
A flaw was found in Apache OpenNLP. A remote attacker can exploit this vulnerability by providing a specially crafted binary model (.bin) file. This file contains an excessively large count field, which leads to an unbounded array allocation and triggers an OutOfMemoryError. Successful exploitation results in a Denial of Service (DoS) against any process that attempts to load the malicious model file.
Statement
Apache's advisory rates this vulnerability Moderate. Red Hat rates it Important (CVSS v3.1 7.5, AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). In an affected deployment, a remote unauthenticated attacker can cause a denial of service if the application loads a crafted OpenNLP binary model. An attacker-controlled count can trigger an OutOfMemoryError during model parsing and stop the affected process. The impact is limited to availability; confidentiality and integrity are not affected. Practical exposure depends on whether the application loads models from a source an attacker can control.
Mitigation
Until the applicable fix is installed, load OpenNLP binary model files only from trusted sources and verify their provenance and integrity. Do not load models supplied by end users or third-party repositories unless they have been verified. Upstream fixes are available in OpenNLP 2.5.9 or later in the 2.x line and 3.0.0-M3 or later in the 3.x line. For Red Hat products, use the fixed package applicable to the product stream, as Red Hat may backport the fix.
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 | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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