Apache Log4j 1.x (EOL) allows Denial of Service (DoS)
** UNSUPPORTED WHEN ASSIGNED ** When using the Chainsaw or SocketAppender components with Log4j 1.x on JRE less than 1.7, an attacker that manages to cause a logging entry involving a specially-crafted (ie deeply nested) hashmap or hashtable (depending on which logging component is in use) to be processed could exhaust the available memory in the virtual machine and achieve Denial of Service when the object is deserialized. This issue affects Apache Log4j before 2. Affected users are recommended to update to Log4j 2.x. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | log4j:log4j | >= 1.0.4, < 2.0 | 2.0 |
| Java / Kotlin (Maven) | org.apache.logging.log4j:log4j-core | >= 1.0.4, < 2.0 | 2.0 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-400, CWE-502- Platform
- Java / Kotlin (Maven)
- Package
log4j:log4j, org.apache.logging.log4j:log4j-core- Disclosed
- 10.03.2023
- Updated
- 11.10.2026 12:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-vp98-w2p3-mv35 - CC BY 4.0
Vulnerability history: org.apache.logging.log4j:log4j-core
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 11
- First → latest
- 01.2020 04.2026
- Without a fix
- 0
- Exploited in attacks
- 2
Severity breakdown
- Critical 3
- High 2
- Medium 5
- Low 1
Disclosures per year
- 2020: 2
- 2021: 3
- 2022: 1
- 2023: 1
- 2024: 0
- 2025: 1
- 2026: 3
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Apache Log4j 1.x (EOL) allows Denial of Service (DoS) this entry
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