CVE-2022-23307Network attack vector

Remote code execution via Chainsaw deserialization

Published Jan 18, 2022 · Updated May 27, 2026

Deserialization of untrusted data in Apache Log4j 1.x allows remote authenticated users to execute code via malicious log entries when Chainsaw runs. The Chainsaw component deserializes serialized contents from received log entries without validating the object types, allowing attacker-controlled data to reach Java deserialization and code-execution gadgets. Exploitation requires Chainsaw to be started with the relevant log transport reachable and the attacker able to supply log entries; successful execution runs with the Chainsaw process privileges.

CVSS severity8.8
High
EPSS probability54.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization of untrusted data in Apache Log4j 1.x allows remote authenticated users to execute code via malicious log entries when Chainsaw runs. The Chainsaw component deserializes serialized contents from received log entries without validating the object types, allowing attacker-controlled data to reach Java deserialization and code-execution gadgets. Exploitation requires Chainsaw to be started with the relevant log transport reachable and the attacker able to supply log entries; successful execution runs with the Chainsaw process privileges.

The record

CVE
CVE-2022-23307
Published
Jan 18, 2022
Updated
May 27, 2026
Vendor
The Apache Software Foundation
Product
Apache Log4j
Classifications
CWE-502, T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 18, 2022CVE publishedPublication date reported by the CVE source.
  2. May 27, 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=1.2.1 <unspecified
  2. Affected versionversion=unspecified <=2.0-alpha1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Apache Software Foundation · Apache Log4jversion=1.2.1 <unspecified; version=unspecified <=2.0-alpha1

Published CVSS scores

9.8GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.8NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

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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