CVE-2026-49361 — fluss-common
HIGHCVE-2026-49361 is a high-severity (CVSS 7.5) vulnerability in org.apache.fluss:fluss-common. A fix is available for org.apache.fluss:fluss-common — see the affected versions and patch details below.
Apache Fluss Netty Frame Decoder Memory Exhaustion Vulnerability
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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-2026-49361.
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
CVE-2026-49361 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 379,842 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
org.apache.fluss:fluss-commonReal-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
Apache Fluss versions prior to 0.9.1 configure the Netty LengthFieldBasedFrameDecoder with Integer.MAX_VALUE as the maximum frame length, allowing unauthenticated remote attackers to exhaust JVM heap memory on TabletServer and CoordinatorServer by sending specially crafted frame headers, resulting in denial of service.
This issue affects Apache Fluss (incubating): 0.8.0 and 0.9.0.
Users are recommended to upgrade to version 0.9.1, which fixes the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.fluss:fluss-common | ≥ 0.8.0-incubating-rc1&&< 0.9.1-incubating | 0.9.1-incubatingorg.apache.fluss:fluss-common:0.9.1-incubating |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.fluss:fluss-common, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.fluss:fluss-common to 0.9.1-incubating or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-49361 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-49361 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-49361. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-49361 in your dependencies?
O3 Security finds CVE-2026-49361 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.