# CVE-2026-49844: log4j: Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities: CVE-2026-49844: 	Improper...

CVE-2026-49844 is fixed in 3 products on 1 platform, first by ALAS2023-2026-2072, released August 31, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-49844
- Priority: Routine
- CVSS: n/a (moderate)
- EPSS: 0.0060
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 31, 2026

## Description

Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities: CVE-2026-49844: 	Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through 2.25.4 and version 2.26.0.  The fix for CVE-2026-34481 did not cover all code paths: when a MapMessage contains a non-finite IEEE 754 value (NaN, Infinity, or -Infinity), MapMessage.asJson() emits the corresponding bare token. RFC 8259 does not permit these tokens, so a conformant parser rejects the resulting document.  The defect is reachable only when both of the following conditions hold:    *  The application uses the  message resolver https://logging.apache.org/log4j/2.x/manual/json-template-layout.html#event-template-resolver-message  of JsonTemplateLayout or any other layout that relies on MapMessage.asJson() or MapMessage.getFormattedMessage(new String[]{"JSON"}).   *  The application logs a MapMessage that contains an attacker-controlled floating-point value.   An attacker who can supply a non-finite value can cause the affected layout to emit malformed JSON, which may corrupt the enclosing log record or disrupt downstream log ingestion and parsing.  Users are advised to upgrade to Apache Log4j API 2.25.5 or 2.26.1, both of which emit RFC 8259-compliant JSON for non-finite values.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | log4j amzn 2023 | 2.17.2-1.amzn2023.0.6 | [ALAS2023-2026-2072](https://patchblox.com/security/data/fix/linux/alas2023-2026-2072.md) | Aug 31, 2026 |
| Linux | log4j-jcl amzn 2023 | 2.17.2-1.amzn2023.0.6 | [ALAS2023-2026-2072](https://patchblox.com/security/data/fix/linux/alas2023-2026-2072.md) | Aug 31, 2026 |
| Linux | log4j-slf4j amzn 2023 | 2.17.2-1.amzn2023.0.6 | [ALAS2023-2026-2072](https://patchblox.com/security/data/fix/linux/alas2023-2026-2072.md) | Aug 31, 2026 |

---

Data as of 2026-11-10T13:56:55Z 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

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.