CVE-2026-50011 — netty-codec-redis
HIGHCVE-2026-50011 is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in io.netty:netty-codec-redis. A fix is available for io.netty:netty-codec-redis — see the affected versions and patch details below.
Netty has unbounded pre-allocation in RedisArrayAggregator from RESP array length
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-2026-50011.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
io.netty:netty-codec-redis☕io.netty:netty-codec-redisReal-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
Summary
RedisArrayAggregator pre-allocates ArrayList with initial capacity equal to the RESP array element count declared in an array header. That count is taken from the wire before the corresponding child messages exist. A small malicious header can claim a huge initial capacity.
Details
The aggregator starts a new aggregation level when it receives an ArrayHeaderRedisMessage. For positive lengths it pushes AggregateState, whose constructor runs new ArrayList<>(length). No configurable maximum is applied in this handler, and the peer does not need to supply the array elements for the backing array allocation to occur.
In the same pipeline, RedisDecoder enforces RedisConstants.REDIS_MESSAGE_MAX_LENGTH for bulk string lengths but does not apply that cap to array header lengths. Declared array sizes can therefore be extremely large while still passing decoding, and the aggregator immediately attempts Object[] reservation.
io.netty.handler.codec.redis.RedisDecoder#decodeLength io.netty.handler.codec.redis.RedisArrayAggregator#decodeRedisArrayHeader
Impact
Availability / resource exhaustion via unbounded pre-allocation from untrusted RESP array headers.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.netty:netty-codec-redis | ≥ 4.2.0.Final&&< 4.2.15.Final | 4.2.15.Finalio.netty:netty-codec-redis:4.2.15.Final |
| ☕Maven | io.netty:netty-codec-redis | all versions | 4.1.135.Finalio.netty:netty-codec-redis:4.1.135.Final |
Affected Products
nettynettyDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.netty:netty-codec-redis, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.netty:netty-codec-redis to 4.2.15.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-50011 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.
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.
This is an Important denial of service vulnerability in Netty's RedisArrayAggregator component. A remote, unauthenticated attacker can exploit this flaw by sending a specially crafted Redis array header, causing excessive memory pre-allocation and leading to resource exhaustion. This can disrupt services utilizing…
To mitigate this issue, restrict network access to services that utilize the netty-codec-redis component and process Redis traffic. Configure firewalls or network access control lists (ACLs) to limit connections to these services from trusted networks or localhost only. This reduces the attack surface by preventing untrusted remote attackers from sending malicious Redis array headers. Consult product-specific documentation for detailed instructions on configuring network access for affected Red Hat products. Reloading or restarting services may be required for network configuration changes to take effect, which could temporarily impact availability.Source: Red Hat security advisory for CVE-2026-50011 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16 | netty-codec-redis | RHSA-2026:37390 |
| Red Hat Data Grid 8.6.2 | netty-codec-redis | RHSA-2026:41951 |
| Red Hat JBoss Enterprise Application Platform 7.4.25 | netty-codec-redis | RHSA-2026:53806 |
| Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7 | eap7-activemq-artemis-0:2.16.0-22.redhat_00057.1.el7eap | RHSA-2026:53644 |
Frequently Asked Questions
Is CVE-2026-50011 in your dependencies?
Find it across Maven, including transitive dependencies.