Memory Allocation with Excessive Size Value Affecting org.apache.opennlp:opennlp-tools package, versions [,2.5.9)[3.0.0-M1,3.0.0-M3)
Threat Intelligence
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The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published8 May 2026
- disclosed4 May 2026
- creditSubramanian S
Introduced: 4 May 2026
CVE-2026-42440 (opens in a new tab)How to fix?
Upgrade org.apache.opennlp:opennlp-tools to version 2.5.9, 3.0.0-M3 or higher.
Overview
org.apache.opennlp:opennlp-tools is an is a machine learning based toolkit for the processing of natural language text.
Affected versions of this package are vulnerable to Memory Allocation with Excessive Size Value in the AbstractModelReader class. An attacker can cause the application to exhaust system memory and crash by supplying a crafted .bin model file with manipulated count fields that trigger unbounded array allocations during deserialization.
Note:
This is only exploitable if the application loads model files from untrusted or semi-trusted sources.
Workaround
This vulnerability can be mitigated by treating all .bin model files as untrusted input unless their provenance is verified, and by avoiding loading models supplied by end users or fetched from third-party repositories without integrity checks.