DEBIAN-CVE-2026-34480
Apache Log4j Core's XmlLayout https://logging.apache.org/log4j/2.x/manual/layouts.html#XmlLayout , in versions up to and including 2.25.3, fails to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/#charsets producing invalid XML output whenever a log message or MDC value contains such characters. The impact depends on the StAX implementation in use: * JRE built-in StAX: Forbidden characters are silently written to the output, producing malformed XML. Conforming parsers must reject such documents with a fatal error, which may cause downstream log-processing systems to drop the affected records. * Alternative StAX implementations (e.g., Woodstox https://github.com/FasterXML/woodstox , a transitive dependency of the Jackson XML Dataformat module): An exception is thrown during the logging call, and the log event is never delivered to its intended appender, only to Log4j's internal status logger. Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue by sanitizing forbidden characters before XML output.
DEBIAN-CVE-2026-34480
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-2026-34480
apache-log4j1.2
Source reference: /affected/0/package/name
- Affected versions
- 1.2.17-11
Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
apache-log4j1.2
Source reference: /affected/1/package/name
- Affected versions
- 1.2.17-11
Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
apache-log4j1.2
Source reference: /affected/2/package/name
- Affected versions
- 1.2.17-11
Source reference:
/affected/2/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
apache-log4j2
Source reference: /affected/3/package/name
- Affected versions
- 2.19.0-2
Source reference:
/affected/3/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
apache-log4j2
Source reference: /affected/4/package/name
- Affected versions
- 2.19.0-2
Source reference:
/affected/4/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
apache-log4j2
Source reference: /affected/5/package/name
- Affected versions
- 2.19.0-2
Source reference:
/affected/5/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": "apache-log4j1.2",
"purl": "pkg:deb/debian/apache-log4j1.2?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"1.2.17-11"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-34480.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "apache-log4j1.2",
"purl": "pkg:deb/debian/apache-log4j1.2?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"1.2.17-11"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-34480.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "apache-log4j1.2",
"purl": "pkg:deb/debian/apache-log4j1.2?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"1.2.17-11"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-34480.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "apache-log4j2",
"purl": "pkg:deb/debian/apache-log4j2?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"2.19.0-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-34480.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "apache-log4j2",
"purl": "pkg:deb/debian/apache-log4j2?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"2.19.0-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-34480.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "apache-log4j2",
"purl": "pkg:deb/debian/apache-log4j2?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"2.19.0-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-34480.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #56434 · Revision 1
- Added to Heist Feed
- Publisher date