GHSA-vmfg-rjjm-rjrj is a critical-severity (CVSS 9.8) Deserialization of Untrusted Data vulnerability in ch.qos.logback:logback-classic. A fix is available for ch.qos.logback:logback-classic — see the affected versions and patch details below.
QOS.ch Logback vulnerable to Deserialization of Untrusted Data
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-vmfg-rjjm-rjrj plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
ch.qos.logback:logback-classic☕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 before 1.2.0 has a serialization vulnerability affecting the SocketServer and ServerSocketReceiver components. The RemoteStreamAppenderClient class in logback-classic and the SocketNode classes in logback-classic and logback-access allow data to be deserialized over a Java Socket, via an ObjectInputStream, without validating the data beforehand. When data is received from the Socket, to be logged, it is deserialized into Java objects.An attacker can exploit this vulnerability by sending malicious, serialized Java objects over the connection to the Socket, which may result in execution of arbitrary code when those objects are deserialized. Note that although logback-core is implicated by the Logback project here, the Sonatype Security Research team discovered that the vulnerability is actually present in the logback-classic and logback-access components. Versions prior to 1.2.0 are vulnerable, as stated in the advisory.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | ch.qos.logback:logback-classic | all versions | 1.2.0ch.qos.logback:logback-classic:1.2.0 |
| ☕Maven | ch.qos.logback:logback-core | all versions | 1.2.0ch.qos.logback:logback-core:1.2.0 |
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-classic, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ch.qos.logback:logback-classic to 1.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vmfg-rjjm-rjrj 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-vmfg-rjjm-rjrj can be triaged on real exposure rather than presence alone.
Tailored to GHSA-vmfg-rjjm-rjrj. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
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.
The vulnerability applies to logback-classic and logback-core.There is no documented evidence in the official upstream advisory that logback-json-core is affected.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Fuse 7.6.0 | logback-core | RHSA-2020:0983 |
| Red Hat JBoss A-MQ 6.3 | camel | RHSA-2017:1832 |
| Red Hat JBoss BPMS 6.4 | logback-core | RHSA-2017:1675 |
| Red Hat JBoss BRMS 6.4 | logback-core | RHSA-2017:1676 |
| Red Hat Satellite 6.4 for RHEL 7 | ansiblerole-insights-client-0:1.5-1.el7sat | RHSA-2018:2927 |
Frequently Asked Questions
Is GHSA-vmfg-rjjm-rjrj in your dependencies?
O3 Security finds GHSA-vmfg-rjjm-rjrj across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.