2026-06-01 Release of logback version 1.5.34

• In case certain StackTraceElement values returned by the Throwable.getStackTrace method are null, StackTraceElementProxy substitutes a dummy instance instead of throwing an IllegalArgumentException. This resolves issues #1040, reported by Naotsugu Kobayashi.

• HardenedObjectInputStream will now throw an InvalidClassException during deserialization attempts of Proxy classes. This change addresses potential deserialization whitelist bypass vulnerability reported by York Shen and registered as CVE-2026-10532.

• A bitwise identical binary of this version can be reproduced by building from source code at commit e62272ac152469aec1ede056c3c7d0d7314e7bfe associated with the tag v_1.5.34. This release was built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2026-05-27 Release of logback version 1.5.33

• PropertiesConfiguratorModelHandler now registers properties file URLs to the ConfigurationWatchList when scan is enabled (via local scan="true" attribute or top-level configuration scan), ensuring changes are detected and reconfiguration occurs. This problem was reported in issues/1034.

• When processing <conversionRule> elements and both class and converterClass attributes are specified, silently use the class attribute without issuing a warning. However, if the attribute values differ, a warning will be issued. This change was requested in issues/1031.

• HardenedModelInputStream will no longer accept to deserialize all classes located under the "java.lang" and "java.util" packages but a limited number of explicitly authorized classes in those packages. This potential deserialization whitelist bypass vulnerability was reported by York Shen and registered as CVE-2026-9828.

• SSL parameters for SSLSocketAppender now enable hostname verification by default. Moreover, the default protocol is now "TLSv1.2". This potential vulnerability was reported by York Shen.

• When printing the status message field, ViewStatusMessagesServletBase now escapes special characters such as "&" as character entities. This potential vulnerability was reported by York Shen.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit 124e8b49b55ac34d08743a0646bd463410192647 associated with the tag v_1.5.33. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2026-02-16 Release of logback version 1.5.32

• In DefaultProcessor, fixed incorrect check for dependencies contained within a parent model. Previous only the direct children were scanned. This fixes logback-access/issues/34.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit e807335a67535b4eacce94e942c0bcb649665d93 associated with the tag v_1.5.32. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2026-02-14 Release of logback version 1.5.31

• Fixed missing META-INF/services directory in logback-classic.jar. This issue rendered logback-classic version 1.5.30 unusable with SLF4J.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit 168e42f9f9a18a3ffdf31eb2bfe80a71e33ecd8b associated with the tag v_1.5.31. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2026-02-14 Release of logback version 1.5.30

• Fix scanning issue when an included file becomes available at a later time. This problem was reported in issues/1021 by Sergey Nazarov.

• Standardized code for version checking across modules.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit 44164f10ca3fb44ce0e68519f13564b87e3aca61 associated with the tag v_1.5.30. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2026-02-09 Release of logback version 1.5.29

• In response to issues/1017, appender names and appender references are once again subject to variable substitution, reverting the change introduced in version 1.5.28.

2026-02-06 Release of logback version 1.5.28

• Appender names or appender references are no longer subject to variable substitution.

• Fixed issue with configurations with conditionals encompassing appenders. This was reported in issues/1016 reported by Sergey Sazonov.

• The element now admits a 'scan' attribute which can be used to override the 'scan' attribute in the element.

• Fixed NullPointerException thrown by VersionUtil.checkForVersionEquality method occurring with GraalVM Native Images. This issue was reported in issues/1014.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit e7a1855ab562bb102333f754603ff89359bf3cfc associated with the tag v_1.5.28. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2026-01-30 Release of logback version 1.5.27

• Updated license to Eclipse Public License version 2.0 from version 1.0, retaining the GPL 2.1 dual-license.

• Fixed missing MDC data transmitted by SocketAppender reported in issues/1010 by Lars Vogel.

• Removed all Receiver classes and components which were already disabled for several years.

• Refactored file scanning code for improved clarity.

• In SizeAndTimeBasedRollingPolicy modified totalSizeCap and maxFileSize comparison to taking into account file compression. This fixes issues/1007.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit 3618eb01aad6672f9cd250dccf7546a69cbe982f associated with the tag v_1.5.27. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2026-01-25 Release of logback version 1.5.26

• InsertFromJNDIModelHandler was accessing javax.naming package forcing the inclusion of the optional java.naming module. This problem was raised in issues/1003 by Marius Hanl who also provided the relevant PR.

• In applications using shadow/fat/shade jars, module or package information could be lost. Thus, in the absence of version information, logback-classic would warn about version mismatches. Logback components now ship with properties files containing version information that survive shadow/fat/shade jars. This issue was reporteed in issues/1002 by Christoph Gritschenberger.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit 33deb54506bbfaf1ff151f26f3a5f86936011619 associated with the tag v_1.5.26. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.

2026-01-17 Release of logback version 1.5.25

• When processing configuration files, logback-core will now only instantiate components compatible with the class expected by the encapsulating class. This fixes an ACE vulnerability recorded as CVE-2026-1225.

• In configuration files, referencing even one undeclared appender would cause all referenced appenders to be skipped. This issue was discovered in issues/997.

• Added VersionUtil class to logback-core. This utility class checks for version compatibility issues and alerts the user if need be.

• Added EpochConverter to output milliseconds/seconds since epoch. This enhancement was requested by Duncan Jauncey in issues/1000 who also provided the relevant implementation PR.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit f426e0002800cfb507f393fcacffe0761a425220 associated with the tag v_1.5.25. Release built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.