UBUNTU-CVE-2026-49844

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Source
https://ubuntu.com/security/CVE-2026-49844
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49844.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-49844
Upstream
Published
2026-07-13T00:00:00Z
Modified
2026-07-13T16:15:35.801830848Z
Severity
  • 6.3 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
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.

References

Affected packages

Ubuntu:18.04:LTS
apache-log4j2

Package

Name
apache-log4j2
Purl
pkg:deb/ubuntu/apache-log4j2?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.8.2-1
2.8.2-2
2.10.0-1
2.10.0-2
2.10.0-2ubuntu0.1
2.12.4-0ubuntu0.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.12.4-0ubuntu0.1",
            "binary_name": "liblog4j2-java"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49844.json"
Ubuntu:20.04:LTS
apache-log4j2

Package

Name
apache-log4j2
Purl
pkg:deb/ubuntu/apache-log4j2?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.11.1-2
2.11.2-1
2.15.0-0.20.04.1
2.16.0-0.20.04.1
2.17.0-0.20.04.1
2.17.1-0.20.04.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.17.1-0.20.04.1",
            "binary_name": "liblog4j2-java"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49844.json"
Ubuntu:22.04:LTS
apache-log4j2

Package

Name
apache-log4j2
Purl
pkg:deb/ubuntu/apache-log4j2?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.13.3-1
2.15.0-1
2.16.0-1
2.17.0-1
2.17.1-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.17.1-1",
            "binary_name": "liblog4j2-java"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49844.json"
Ubuntu:24.04:LTS
apache-log4j2

Package

Name
apache-log4j2
Purl
pkg:deb/ubuntu/apache-log4j2?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.19.0-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.19.0-2",
            "binary_name": "liblog4j2-java"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49844.json"
Ubuntu:26.04:LTS
apache-log4j2

Package

Name
apache-log4j2
Purl
pkg:deb/ubuntu/apache-log4j2?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.19.0-2
2.19.0-2build1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.19.0-2build1",
            "binary_name": "liblog4j2-java"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49844.json"
Ubuntu:Pro:16.04:LTS
apache-log4j2

Package

Name
apache-log4j2
Purl
pkg:deb/ubuntu/apache-log4j2?arch=source&distro=esm-apps%2Fxenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.2-1
2.4-1
2.4-2
2.4-2ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.4-2ubuntu0.1~esm1",
            "binary_name": "liblog4j2-java"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49844.json"