Description
Improper Output Neutralization for Logs vulnerability in Apache Log4cxx.
When using JSONLayout, not all payload bytes are properly escaped. If an attacker-supplied message contains certain non-printable characters, these will be passed along in the message and written out as part of the JSON message. This may prevent applications that consume these logs from correctly interpreting the information within them.
This issue affects Apache Log4cxx: before 1.5.0.
Users are recommended to upgrade to version 1.5.0, which fixes the issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache Log4cxx | 0.11.0 – < 1.5.0 | 1.5.0 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | log4cxx | 1.4.0-1.1 | — |
| Debian 13 | log4cxx | 1.4.0-1+deb13u1 | — |
| Debian 12 | log4cxx | 1.0.0-1+deb12u1 | — |
| Debian 11 | log4cxx | 0.11.0-2+deb11u1 | DLA-4322-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | log4cxx | No fix yet | — |
| Ubuntu 25.10 | log4cxx | No fix yet | — |
| Ubuntu 24.04 LTS | log4cxx | No fix yet | — |
| Ubuntu 22.04 LTS | log4cxx | No fix yet | — |
| Ubuntu 20.04 LTS | log4cxx | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | log4cxx | No fix yet | — |
| Ubuntu 16.04 LTS | log4cxx | No fix yet | — |
| Ubuntu 14.04 LTS | log4cxx | No fix yet | — |
Advisories 1
- DLA-4322-1 log4cxx - security update Debian Security (DSA / DLA) · Oct 5, 2025