DEBIAN-CVE-2026-40023
Apache Log4cxx's XMLLayout https://logging.apache.org/log4cxx/1.7.0/classlog4cxx_1_1xml_1_1XMLLayout.html , in versions before 1.7.0, fails to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/#charsets in log messages, NDC, and MDC property keys and values, producing invalid XML output. Conforming XML parsers must reject such documents with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records. An attacker who can influence logged data can exploit this to suppress individual log records, impairing audit trails and detection of malicious activity. Users are advised to upgrade to Apache Log4cxx 1.7.0, which fixes this issue.
DEBIAN-CVE-2026-40023
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-40023
log4cxx
Source reference: /affected/0/package/name
- Affected versions
- 1.0.0-1
Source reference:
/affected/0/versions1.0.0-1+deb12u1Source reference:
/affected/0/versions1.1.0-1Source reference:
/affected/0/versions1.1.0-1~exp1Source reference:
/affected/0/versions1.2.0-1Source reference:
/affected/0/versions1.3.0-1Source reference:
/affected/0/versions1.3.1-1Source reference:
/affected/0/versions1.4.0-1Source reference:
/affected/0/versions1.4.0-1.1Source reference:
/affected/0/versions1.5.0-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
log4cxx
Source reference: /affected/1/package/name
- Affected versions
- 1.4.0-1
Source reference:
/affected/1/versions1.4.0-1+deb13u1Source reference:
/affected/1/versions1.4.0-1.1Source reference:
/affected/1/versions1.5.0-1Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
log4cxx
Source reference: /affected/2/package/name
- Affected versions
- 1.4.0-1
Source reference:
/affected/2/versions1.4.0-1.1Source reference:
/affected/2/versions1.5.0-1Source reference:
/affected/2/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "log4cxx",
"purl": "pkg:deb/debian/log4cxx?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"1.0.0-1",
"1.0.0-1+deb12u1",
"1.1.0-1",
"1.1.0-1~exp1",
"1.2.0-1",
"1.3.0-1",
"1.3.1-1",
"1.4.0-1",
"1.4.0-1.1",
"1.5.0-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-40023.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "log4cxx",
"purl": "pkg:deb/debian/log4cxx?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"1.4.0-1",
"1.4.0-1+deb13u1",
"1.4.0-1.1",
"1.5.0-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-40023.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "log4cxx",
"purl": "pkg:deb/debian/log4cxx?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"1.4.0-1",
"1.4.0-1.1",
"1.5.0-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-40023.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #56945 · Revision 1
- Added to Heist Feed
- Publisher date