CVE-2026-43825Public exploitNetwork attack vector

Remote code execution via unfiltered Java deserialization

Published Jul 6, 2026 · Updated Jul 6, 2026

Unsafe Java deserialization in Apache OpenNLP ML LibSVM before 3.0.0-M4 allows remote attackers to execute code via a crafted model stream. SvmDoccatModel.deserialize(InputStream) calls ObjectInputStream.readObject() without an ObjectInputFilter, materializing the supplied object graph before checking its type. Reachability requires an embedding application to load an attacker-controlled stream and an exploitable gadget chain to exist on that application's classpath.

CVSS severity7.3
High
EPSS probability13.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe Java deserialization in Apache OpenNLP ML LibSVM before 3.0.0-M4 allows remote attackers to execute code via a crafted model stream. SvmDoccatModel.deserialize(InputStream) calls ObjectInputStream.readObject() without an ObjectInputFilter, materializing the supplied object graph before checking its type. Reachability requires an embedding application to load an attacker-controlled stream and an exploitable gadget chain to exist on that application's classpath.

The record

CVE
CVE-2026-43825
Published
Jul 6, 2026
Updated
Jul 6, 2026
Vendor
The Apache Software Foundation
Product
Apache OpenNLP ML LibSVM
Classifications
CWE-502, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.0.0-M1 <3.0.0-M4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache OpenNLP ML LibSVMversion=3.0.0-M1 <3.0.0-M4

Published CVSS scores

7.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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