log4j-api-2.18.0.jar: 1 vulnerabilities (highest severity is: 5.8)

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Vulnerable Library - log4j-api-2.18.0.jar

The Apache Log4j API

Library home page: https://www.apache.org/

Path to vulnerable library: /tde/core-net/3.0/lib/log4j-api-2.18.0.jar

Vulnerabilities

Vulnerability	Severity	CVSS	Exploit Maturity	EPSS	Dependency	Type	Fixed in (log4j-api version)	Remediation Possible**	Reachability
CVE-2026-49844	Medium	5.8	Not Defined		log4j-api-2.18.0.jar	Direct	2.25.5	❌

**In some cases, Remediation PR cannot be created automatically for a vulnerability despite the availability of remediation

Details

CVE-2026-49844

Vulnerable Library - log4j-api-2.18.0.jar

The Apache Log4j API

Library home page: https://www.apache.org/

Path to vulnerable library: /tde/core-net/3.0/lib/log4j-api-2.18.0.jar

Dependency Hierarchy:

• ❌ log4j-api-2.18.0.jar (Vulnerable Library)

Found in base branch: master

Vulnerability Details

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.

Publish Date: 2026-07-10

URL: CVE-2026-49844

Threat Assessment

Exploit Maturity: Not Defined

EPSS:

CVSS 3 Score Details (5.8)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Changed
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: Low
  • Availability Impact: None

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Origin: https://logging.apache.org/security.html#CVE-2026-49844

Release Date: 2026-07-10

Fix Resolution: 2.25.5