CVE-2025-54812
Apache Log4cxx: Improper HTML escaping in HTMLLayout
Improper Output Neutralization for Logs vulnerability in Apache Log4cxx.
When using HTMLLayout, logger names are not properly escaped when writing out to the HTML file. If untrusted data is used to retrieve the name of a logger, an attacker could theoretically inject HTML or Javascript in order to hide information from logs or steal data from the user. In order to activate this, the following sequence must occur:
-
Log4cxx is configured to use HTMLLayout.
-
Logger name comes from an untrusted string
-
Logger with compromised name logs a message
-
User opens the generated HTML log file in their browser, leading to potential XSS
Because logger names are generally constant strings, we assess the impact to users as LOW
This issue affects Apache Log4cxx: before 1.5.0.
Users are recommended to upgrade to version 1.5.0, which fixes the issue.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Active
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
2.1
Apache Log4cxx: Improper HTML escaping in HTMLLayout
Improper Output Neutralization for Logs vulnerability in Apache Log4cxx.
When using HTMLLayout, logger names are not properly escaped when writing out to the HTML file. If untrusted data is used to retrieve the name of a logger, an attacker could theoretically inject HTML or Javascript in order to hide information from logs or steal data from the user. In order to activate this, the following sequence must occur:
-
Log4cxx is configured to use HTMLLayout.
-
Logger name comes from an untrusted string
-
Logger with compromised name logs a message
-
User opens the generated HTML log file in their browser, leading to potential XSS
Because logger names are generally constant strings, we assess the impact to users as LOW
This issue affects Apache Log4cxx: before 1.5.0.
Users are recommended to upgrade to version 1.5.0, which fixes the issue.
- Record
CVE-2025-54812- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N - Weakness
- CWE-117
- Updated
- 2026-11-02
EUVDEUVD-2025-25621
2.1
Improper Output Neutralization for Logs vulnerability in Apache Log4cxx.
When using HTMLLayout, logger names are not properly escaped when writing out to the HTML file. If untrusted data is used to retrieve the name of a logger, an attacker could theoretically inject HTML or Javascript in order to hide information from logs or steal data from the user. In order to activate this, the following sequence must occur:
-
Log4cxx is configured to use HTMLLayout.
-
Logger name comes from an untrusted string
-
Logger with compromised name logs a message
-
User opens the generated HTML log file in their browser, leading to potential XSS
Because logger names are generally constant strings, we assess the impact to users as LOW
This issue affects Apache Log4cxx: before 1.5.0.
Users are recommended to upgrade to version 1.5.0, which fixes the issue.
- Record
EUVD-2025-25621- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-7mpr-gcjx-jcmw
2.1
Improper Output Neutralization for Logs vulnerability in Apache Log4cxx. When using HTMLLayout,...
Improper Output Neutralization for Logs vulnerability in Apache Log4cxx.
When using HTMLLayout, logger names are not properly escaped when writing out to the HTML file. If untrusted data is used to retrieve the name of a logger, an attacker could theoretically inject HTML or Javascript in order to hide information from logs or steal data from the user. In order to activate this, the following sequence must occur:
-
Log4cxx is configured to use HTMLLayout.
-
Logger name comes from an untrusted string
-
Logger with compromised name logs a message
-
User opens the generated HTML log file in their browser, leading to potential XSS
Because logger names are generally constant strings, we assess the impact to users as LOW
This issue affects Apache Log4cxx: before 1.5.0.
Users are recommended to upgrade to version 1.5.0, which fixes the issue.
- Record
GHSA-7mpr-gcjx-jcmw- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-117
- Updated
- 2026-11-02
NVD
2.1
Improper Output Neutralization for Logs vulnerability in Apache Log4cxx.
When using HTMLLayout, logger names are not properly escaped when writing out to the HTML file. If untrusted data is used to retrieve the name of a logger, an attacker could theoretically inject HTML or Javascript in order to hide information from logs or steal data from the user. In order to activate this, the following sequence must occur:
-
Log4cxx is configured to use HTMLLayout.
-
Logger name comes from an untrusted string
-
Logger with compromised name logs a message
-
User opens the generated HTML log file in their browser, leading to potential XSS
Because logger names are generally constant strings, we assess the impact to users as LOW
This issue affects Apache Log4cxx: before 1.5.0.
Users are recommended to upgrade to version 1.5.0, which fixes the issue.
- Record
CVE-2025-54812- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-117
- Updated
- 2026-11-02
OSV
2.1
Apache Log4cxx: Improper HTML escaping in HTMLLayout
Improper Output Neutralization for Logs vulnerability in Apache Log4cxx.
When using HTMLLayout, logger names are not properly escaped when writing out to the HTML file. If untrusted data is used to retrieve the name of a logger, an attacker could theoretically inject HTML or Javascript in order to hide information from logs or steal data from the user. In order to activate this, the following sequence must occur:
-
Log4cxx is configured to use HTMLLayout.
-
Logger name comes from an untrusted string
-
Logger with compromised name logs a message
-
User opens the generated HTML log file in their browser, leading to potential XSS
Because logger names are generally constant strings, we assess the impact to users as LOW
This issue affects Apache Log4cxx: before 1.5.0.
Users are recommended to upgrade to version 1.5.0, which fixes the issue.
- Record
CVE-2025-54812- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N - Weakness
- CWE-117
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2025-54812
5.4
Improper Output Neutralization for Logs vulnerability in Apache Log4cxx. When using HTMLLayout, logger names are not properly escaped when writing out to the HTML file. If untrusted data is used to retrieve the name of a logger, an attacker could theoretically inject HTML or Javascript in order to hide information from logs or steal data from the user. In order to activate this, the following sequence must occur: * Log4cxx is configured to use HTMLLayout. * Logger name comes from an untrusted string * Logger with compromised name logs a message * User opens the generated HTML log file in their browser, leading to potential XSS Because logger names are generally constant strings, we assess the impact to users as LOW This issue affects Apache Log4cxx: before 1.5.0. Users are recommended to upgrade to version 1.5.0, which fixes the issue.
- Record
DEBIAN-CVE-2025-54812- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2025-54812
2.1
Improper Output Neutralization for Logs vulnerability in Apache Log4cxx. When using HTMLLayout, logger names are not properly escaped when writing out to the HTML file. If untrusted data is used to retrieve the name of a logger, an attacker could theoretically inject HTML or Javascript in order to hide information from logs or steal data from the user. In order to activate this, the following sequence must occur: * Log4cxx is configured to use HTMLLayout. * Logger name comes from an untrusted string * Logger with compromised name logs a message * User opens the generated HTML log file in their browser, leading to potential XSS Because logger names are generally constant strings, we assess the impact to users as LOW This issue affects Apache Log4cxx: before 1.5.0. Users are recommended to upgrade to version 1.5.0, which fixes the issue.
- Record
UBUNTU-CVE-2025-54812- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N - CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2025:15549-1 No score
liblog4cxx-devel-1.5.0-1.1 on GA media
These are all security issues fixed in the liblog4cxx-devel-1.5.0-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2025:15549-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
log4cxxDebian:12 |
before 1.0.0-1+deb12u1, plus listed versions 1.0.0-1 |
1.0.0-1+deb12u1 |
log4cxxDebian:13 |
before 1.4.0-1+deb13u1, plus listed versions 1.4.0-1 |
1.4.0-1+deb13u1 |
log4cxxDebian:14 |
before 1.4.0-1.1, plus listed versions 1.4.0-1 |
1.4.0-1.1 |
log4cxxDebian:11 From an advisory covering 2 CVEs |
before 0.11.0-2+deb11u1, plus listed versions 0.11.0-2 |
0.11.0-2+deb11u1 |
log4cxxUbuntu:14.04:LTS |
All versions, plus listed versions 0.10.0-1.2ubuntu3 |
None known |
log4cxxUbuntu:16.04:LTS |
All versions, plus listed versions 0.10.0-9ubuntu10.10.0-9ubuntu20.10.0-10ubuntu1 |
None known |
log4cxxUbuntu:18.04:LTS |
All versions, plus listed versions 0.10.0-12ubuntu10.10.0-13ubuntu10.10.0-13ubuntu2 |
None known |
log4cxxUbuntu:20.04:LTS |
All versions, plus listed versions 0.10.0-15ubuntu10.10.0-15ubuntu2 |
None known |
log4cxxUbuntu:22.04:LTS |
All versions, plus listed versions 0.11.0-2ubuntu10.11.0-3ubuntu20.12.1-4 |
None known |
log4cxxUbuntu:24.04:LTS |
All versions, plus listed versions 1.1.0-11.1.0-1build11.1.0-1build21.1.0-1build3 |
None known |
log4cxxUbuntu:25.10 |
All versions, plus listed versions 1.3.1-11.4.0-1 |
None known |
log4cxxUbuntu:26.04:LTS |
All versions, plus listed versions 1.4.0-11.5.0-1 |
None known |
log4cxxopenSUSE:Tumbleweed |
before 1.5.0-1.1 | 1.5.0-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-54812 is a low vulnerability (CVSS 2.1) in Apache Log4cxx, published August 22, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.24%, the 69th percentile. Fixed in log4cxx 1.0.0-1+deb12u1.
References
logging.apache.org/security.html
github.com/apache/logging-log4cxx/pull/509
github.com/apache/logging-log4cxx/pull/514
lists.debian.org/debian-lts-announce/2025/10/msg00002.html
openwall.com/lists/oss-security/2025/08/22/2
nvd.nist.gov/vuln/detail/CVE-2025-54812
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github.com/advisories/GHSA-7mpr-gcjx-jcmw
github.com/CVEProject/cvelistV5/tree/main/cves/2025/54xxx/CVE-2025-54812.json
security-tracker.debian.org/tracker/CVE-2025-54812
ubuntu.com/security/CVE-2025-54812
cve.org/CVERecord?id=CVE-2025-54812
github.com/apache/logging-log4cxx/commit/1c599de956ae9eedd8b5e3f744bfb867c39e8bba
github.com/apache/logging-log4cxx/commit/36d829e9f6c3f9f4f9a42e22df326a9ed7b6e373
suse.com/security/cve/CVE-2025-54812