CVE-2026-44890 — netty-codec-redis
HIGHCVE-2026-44890 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 Direct Memory Consumption in its RedisDecoder
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-2026-44890.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-44890 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 380,066 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
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
An attacker can cause DoS by sending crafted Redis payloads across multiple connections without \r\n. This exhausts the server's direct memory pool (OutOfDirectMemoryError), preventing legitimate connections from being processed.
Details
io.netty.handler.codec.redis.RedisDecoder decodes the length of bulk strings and array headers using the decodeLength method. This method reads bytes from the network until it encounters a \n character. However, it does not enforce any maximum length check while buffering the bytes if the \n character is not found. An attacker can exploit this by sending a continuous stream of digits (e.g., $1111...) without ever sending a \n.
To cause a true Denial of Service, an attacker must open multiple concurrent connections and distribute the unbounded payloads among them.
According to the RESP specification (https://redis.io/docs/latest/develop/reference/protocol-spec/), all parts of the protocol are strictly terminated with \r\n. Furthermore, the length prefix itself is an integer representation that must fit within standard numeric limits (e.g., a 64-bit signed integer). Therefore, a stream of digits exceeding these bounds without \r\n is a protocol violation and should be rejected immediately rather than buffered indefinitely.
Impact
Denial of Service due to memory exhaustion. Any application using Netty's RedisDecoder to handle untrusted Redis traffic is vulnerable.
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-2026-44890 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 flaw is rated as Important as it allows a remote, unauthenticated attacker to cause a denial of service in applications utilizing `netty-codec-redis` or `netty-handler`. By sending specially crafted Redis payloads without proper termination, an attacker can exhaust the server's direct memory pool, preventing…
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-2026-44890 (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 | io.netty/netty-codec-redis:4.1.135.Final-redhat-00001 | 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 |
| Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8 | eap7-activemq-artemis-0:2.16.0-22.redhat_00057.1.el8eap | RHSA-2026:53645 |
| Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 9 | eap7-activemq-artemis-0:2.16.0-22.redhat_00057.1.el9eap | RHSA-2026:53646 |
| Red Hat JBoss Enterprise Application Platform 8.1 | netty-codec-redis | RHSA-2026:50085 |
Frequently Asked Questions
Is CVE-2026-44890 in your dependencies?
Find it across Maven, including transitive dependencies.