CVE-2025-11226 — logback-core
Fix: qos-ch/logback@61f6a25CVE-2025-11226 is a Improper Input Validation vulnerability in ch.qos.logback:logback-core. A fix is available for ch.qos.logback:logback-core — see the affected versions and patch details below.
QOS.CH logback-core is vulnerable to Arbitrary Code Execution through file processing
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-11226.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
ch.qos.logback:logback-core☕ch.qos.logback:logback-coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
QOS.CH logback-core versions up to 1.5.18 contain an ACE vulnerability in conditional configuration file processing in Java applications. This vulnerability allows an attacker to execute arbitrary code by compromising an existing logback configuration file or by injecting a malicious environment variable before program execution.
A successful attack requires the Janino library and Spring Framework to be present on the user's class path. Additionally, 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 privileges.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | ch.qos.logback:logback-core | ≥ 1.4.0&&< 1.5.19 | 1.5.19ch.qos.logback:logback-core:1.5.19 |
| ☕Maven | ch.qos.logback:logback-core | all versions | 1.3.16ch.qos.logback:logback-core:1.3.16 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ch.qos.logback:logback-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ch.qos.logback:logback-core to 1.5.19 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-11226 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.Source: Red Hat security advisory for CVE-2025-11226 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2025-11226 in your dependencies?
Find it across Maven, including transitive dependencies.