CVE-2025-54812
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in, but needs a user to act. Limited direct impact.
- Exploit odds
- 1.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.2% in the next 30 days (EPSS).
- Severity: 2.1 LOW (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 1.2% · EPSS, next 30 days
- Weakness
- CWE-117
- Record status
- Modified
Affected
- Apache log4cxx < 1.5.0
Attack profile CVSS 4.0 · 2.1
- Attack vector
- Network
- Complexity
- High
- Attack requirements
- None
- Privileges needed
- None
- User interaction
- Active
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Raw vector
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
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-54812.md and follow it. Check whether this project is affected by CVE-2025-54812. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/apache/logging-log4cxx/pull/509
- https://github.com/apache/logging-log4cxx/pull/514
- https://logging.apache.org/security.html#CVE-2025-54812