CVE-2026-13006
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedACE vulnerability in conditional configuration file processing by QOS.CH logback-core up to and including version 1.5.36 in Java applications, allows an attacker to execute arbitrary code circumventing existing protections against CVE-2025-11226 by compromising an existing logback configuration file or by injecting an environment variable before program execution. A successful attack requires the presence of Janino library to be present on the user's class path. In addition, the attacker must have write access to a configuration file. Alternatively, the attacker could inject a malicious environment variable pointing to a malicious configuration file. In both cases, the attack requires existing privilege. Please note that in logack version 1.5.37 conditional processing using Janino was removed.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceACE vulnerability in logback-core's conditional configuration file processing allows attackers with existing privilege to execute arbitrary code by either compromising a logback configuration file or injecting a malicious environment variable pointing to a crafted config. The attack requires the Janino library on the classpath and bypasses protections against CVE-2025-11226.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- High
- Authentication
- None
- User interaction
- None
- Scope
- P
CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/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:P/AU:N/R:X/V:X/RE:M/U:Green
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify logback-core versionLocate the logback-core JAR file in your classpath or dependency management system (Maven pom.xml, Gradle build.gradle, or the JAR file itself). Run 'jar tf logback-core-*.jar | head' to find the manifest or use 'mvn dependency:list' to list installed versions.Affected if The installed version is earlier than 1.5.37 (or you cannot confirm it is 1.5.37 or later)
-
Confirm Janino library presenceSearch for Janino JAR files in your classpath or dependencies. Run 'find . -name "janino*"' or check your dependency tree with 'mvn dependency:tree | grep janino'. Also inspect WEB-INF/lib or lib directories for janino*.jar files.Affected if The Janino library (janino.jar or commons-compiler.jar) is present on the classpath - this is a required condition for the vulnerability to be exploitable
-
Verify configuration file access controlsCheck file permissions on logback.xml, logback-test.xml, and logback.groovy configuration files in your application. Run 'ls -la' on these files if they exist in your deployment. Also check for any custom configuration paths set via system properties.Affected if The logback configuration files are writable by untrusted users or processes, or if arbitrary users can modify environment variables controlling logback configuration paths
-
Review environment variable exposureInspect which environment variables your application reads that could control logback configuration. Check for LOGBACK_CONFIG_FILE, LOGBACK_CONFIG_FILE, or any custom environment variables referenced in your startup scripts. Run 'env | grep -i logback' on systems running the application.Affected if Environment variables pointing to logback configuration files can be influenced by attackers or are exposed in shared/containerized environments with insufficient isolation
Your environment is affected if logback-core version is earlier than 1.5.37, Janino library is present on the classpath, and attackers can influence logback configuration files or related environment variables.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade to logback-core version 1.5.37 or later, which removes Janino-based conditional processing; alternatively, remove Janino from the classpath and restrict write access to configuration files and environment variables.
logback-core version 1.5.37 or later
- Identify all Java applications using logback-core with Janino library on the classpath
- Update Maven dependency: change logback-core version to 1.5.37 or later (e.g., <groupId>ch.qos.logback</groupId><artifactId>logback-core</artifactId><version>1.5.37</version>)
- If using Gradle, update to: implementation 'ch.qos.logback:logback-core:1.5.37'
- Review application configuration files for any Janino-based conditional processing that may no longer work after upgrade
- Test application functionality to ensure logging behavior is correct post-upgrade
- Ensure no other dependencies require older vulnerable logback versions
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,072.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-13006 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-13006 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data