CVE-2026-43825

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Source
https://cve.org/CVERecord?id=CVE-2026-43825
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43825.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-43825
Downstream
Published
2026-07-06T15:42:04.928Z
Modified
2026-07-15T01:49:00.698679Z
Severity
  • 7.3 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L CVSS Calculator
Summary
Apache OpenNLP :: Core :: ML :: LibSVM: Unsafe Java Deserialization in SvmDoccatModel
Details

Untrusted Java Deserialization in Apache OpenNLP SvmDoccatModel

Versions Affected:   before 3.0.0-M4 (libsvm document categorization module; introduced in   OPENNLP-1808 and only present on the 3.x line)

Description: SvmDoccatModel.deserialize(InputStream) reads an attacker-controlled stream with java.io.ObjectInputStream and calls readObject() without an ObjectInputFilter installed. ObjectInputStream materialises every class referenced in the stream before the resulting object is cast to SvmDoccatModel, so the cast that follows readObject() executes only after the foreign object graph has already been deserialised in full.

If a Java deserialization gadget chain is available on the consumer's classpath, a crafted payload supplied to deserialize() executes arbitrary code in the JVM that loads it. Apache OpenNLP itself does not ship a known gadget chain, so the realistic risk is to downstream applications that embed the libsvm module alongside vulnerable transitive dependencies. The method is public and static, so any caller can pass an untrusted stream to it directly.

The practical impact is remote code execution against processes that load SvmDoccatModel instances from untrusted or semi-trusted origins.

Mitigation:

3.x users should upgrade to 3.0.0-M4.

Users who cannot upgrade immediately should treat all serialized SvmDoccatModel streams as untrusted input unless their provenance is verified, and should avoid invoking SvmDoccatModel.deserialize() on streams supplied by end users or fetched from third-party sources without integrity checks.

Database specific 
{
    "cna_assigner": "apache",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43825.json",
    "unresolved_ranges": [
        {
            "source": "AFFECTED_FIELD",
            "extracted_events": [
                {
                    "introduced": "3.0.0-M1"
                },
                {
                    "fixed": "3.0.0-M4"
                }
            ]
        },
        {
            "source": "DESCRIPTION",
            "extracted_events": [
                {
                    "fixed": "3.0.0-M4"
                }
            ]
        }
    ],
    "cwe_ids": [
        "CWE-502"
    ]
}
References

Affected packages

Git / github.com/apache/opennlp

Affected ranges

Type
GIT
Repo
https://github.com/apache/opennlp
Events
Introduced
1e9f4d89af6ebc5b6860087589146817dff08b44
Last affected
416029e32ab67cbe99c3e3964c4609af3dd5775b
Database specific 
{
    "cpe": [
        "cpe:2.3:a:apache:opennlp:3.0.0:m1:*:*:*:*:*:*",
        "cpe:2.3:a:apache:opennlp:3.0.0:m2:*:*:*:*:*:*",
        "cpe:2.3:a:apache:opennlp:3.0.0:m3:*:*:*:*:*:*"
    ],
    "source": "CPE_STRING",
    "extracted_events": [
        {
            "introduced": "3.0.0-m1"
        },
        {
            "last_affected": "3.0.0-m1"
        },
        {
            "introduced": "3.0.0-m2"
        },
        {
            "last_affected": "3.0.0-m2"
        },
        {
            "introduced": "3.0.0-m3"
        },
        {
            "last_affected": "3.0.0-m3"
        }
    ]
}

Affected versions

3.*
3.0.0-m1
3.0.0-m2
3.0.0-m3

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43825.json"