2026-01-06 Release of logback version 1.5.24

• Added ExpressionPropertyCondition a PropertyCondition that can evaluate boolean expressions similar to Java. See the relevant documentation for further details.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit 62bc5fc245dd3a52f3dd45e232733f4cefb4806d associated with the tag v_1.5.24. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2025-12-21 Release of logback version 1.5.23

• In response to issues/959 file name collisions are detected at configuration time by analyzing the configuration file and no longer at run time. This avoids the ConcurrentModificationException reported in the issue.

• ZIP and XZ compression now use a BufferedOutputStream when writing to the compressed file. This issue was reported in issues/988.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit 0bcc3feb54a6d99caac70969ee5f8334aad1fbaf associated with the tag v_1.5.23. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2025-12-11 Release of logback version 1.5.22

• In order to prevent involuntary information leakage, Logback will no longer output the value of a substituted variable, if the variable name contains any of the case-insensitive strings "password", "secret" or "confidential". This problem was reported by Chintan Rohila in issues/986.

• Logback now takes the overridden toString() method of Throwable subclasses into account when printing stack traces. This issue was reported in LOGBACK-543 by Alvin Chee, with a fix provided in PR 404 by Brett Kail.

• Instead of limit-counting guard, Logback now uses a tumbling-window guard to rate limit internal error messages.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit 572379aabd2f672b49593e4020696c624541e5b0 associated with the tag v_1.5.22. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2025-11-10 Release of logback version 1.5.21

• Invocations of turbo filters in isDebugEnabled, isInfoEnabled()... remain as they were, untouched. However, any installed instances of TurboFilter are now invoked also from within the log(LoggingEvent) method of Logger with the contents of the LoggingEvent, typically via the fluent API. This fixes issues/871.

• Removed reentry-guard in most subclasses of UnsynchronizedAppenderBase where it was not needed.

• Initialization procedure has been simplified by removing the step instantiating a SerializedModelConfigurator. However, it is still possible to set up SerializedModelConfigurator as a custom configurator.

• JsonEncoder is now friendlier to derivation by sub-classes as requested in issues/979.

• Fixed XMLLayout thread safety issue reported in LOGBACK-427.

• Removed superfluous buffering in Zip, GZ and XZ compression code.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit fed6f37ffe3449e40f6a9fffe050936a33116bd1 associated with the tag v_1.5.21. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2025-10-19 Release of logback version 1.5.20

• Due to potential vulnerabilities associated with dynamic, i.e. runtime, java code compilation and execution (using Janino), the 'condition' attribute within the <if> element is deprecated and will be removed in 2027.

An online migration service is provided to help with the transition.

The <condition> element, new in this version, admits custom PropertyEvaluator as a recommended alternative. See also the updated documentation on conditional configuration.

• Logback-classic's initialization procedure has been simplified by removing the step instantiating a SerializedModelConfigurator. However, it is still possible to set up SerializedModelConfigurator as a custom configurator.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit 930fb15c993a4344bcecc6ba2225c12a2c38e676 associated with the tag v_1.5.20. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2025-09-30 Release of logback version 1.5.19

• Disallow "new" operator in the condition attribute of <if> elements. This fixes an ACE vulnerability recorded as CVE-2025-11226.

• At initialization time, slightly better reporting about watched configuration files.

• Softer message regarding usage of ConsoleAppender and its potential impact on performance.

• In ViewStatusMessagesServlet, restrict processing of "Clear" button to POST method. This change was proposed by Ralf Wiebicke who also provided the relevant PR.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit e572d4f87f06674788eb3ca7148e8d1dffc615fa associated with the tag v_1.5.19. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2025-03-18 Release of logback version 1.5.18

• Added support for XZ compression for archived log files. Note that XZ compression requires Tukaani project's XZ library for Java. In case XZ compression is requested but the XZ library is missing, then logback will substitute GZ compression as a fallback. This feature was requested in issues/755.

• Removed references to java.security.AccessController class. This class has been deprecated for some time and is slated for removal in future JDK versions.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit b2a02f065379a9b1ba5ff837fc08913b744774bc associated with the tag v_1.5.18. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2025-02-25 Release of logback version 1.5.17

• Fixed Jansi 2.4.0 color-coded output not working on Windows CMD.exe console when the default terminal application is set to "Windows Console Host". This problem was reported in issues/753 by Michael Lyubkin.

• Fixed race condition occurring in case MDC class is initialized while org.slf4j.LoggerFactory is initializing logback-classic's LoggerContext. When this race conditions occurs, the MDCAdapter instance used by MDC does not match the instance used by logback-classic. This issue was reported in SLF4J issues/450. While logback-classic version 1.5.17 remains compatible with SLF4J versions in the 2.0.x series, fixing this particular MDC issue requires SLF4J version 2.0.17.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit 10358724ed723b3745c010aa40cb02a2dfed4593 associated with the tag v_1.5.17. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2025-01-05 Release of logback version 1.5.16

• In order to ease the migration of configuration files depending on JaninoEventEvaluator, logback-classic will emit a warning about the removal of JaninoEventEvaluator in version 1.5.13 and suggest an online migration tool.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit 74c9ebd0e784d9e9ffc6c627cf5016d0157956b2 associated with the tag v_1.5.16. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.