# CVE-2020-9488: liblog4j2-java: Improper validation of certificate with host mismatch in Apache Log4j SMTP appender

CVE-2020-9488 is fixed in liblog4j2-java on 1 platform by liblog4j2-java 2.16.0-0.20.04.1 (version 2.16.0-0.20.04.1), released December 14, 2021. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2020-9488
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0822
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 27, 2020

## Description

Improper validation of certificate with host mismatch in Apache Log4j SMTP appender. This could allow an SMTPS connection to be intercepted by a man-in-the-middle attack which could leak any log messages sent through that appender. Fixed in Apache Log4j 2.12.3 and 2.13.1

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | liblog4j2-java Ubuntu 20.04 LTS (focal) | 2.16.0-0.20.04.1 | [liblog4j2-java 2.16.0-0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-liblog4j2-java-2.16.0-0.20.04.1.md) | Dec 14, 2021 |

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Data as of 2026-11-07T18:46:35Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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