Netty: Unbounded pre-allocation in RedisArrayAggregator from RESP array length

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-50011: 0.46% estimated exploitation activity in the next 30 days; percentile 39.99 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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.REDISMESSAGEMAXLENGTH 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…

Published by the source

15 Jun 2026, 20:46 UTC

Last modified by the source

15 Jun 2026, 20:46 UTC

Source last checked

26 Oct 2026, 16:53 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-5w86-c3rq-vjj7

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# Patch Next advisory brief: CVE-2026-50011

Advisory: Netty: Unbounded pre-allocation in RedisArrayAggregator from RESP array length
IDs: CVE-2026-50011, GHSA-5w86-c3rq-vjj7
Record: https://patchnext.com/advisories/cve-2026-50011 (revision 1, source checked 26 Oct 2026, 16:53 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: io.netty:netty-codec-redis 4.2.15.Final, 4.1.135.Final. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven io.netty:netty-codec-redis: affected >= 4.2.0.Final, <= 4.2.14.Final; <= 4.1.134.Final; fixed in 4.2.15.Final, 4.1.135.Final

## Suggested inspection (read-only)
- Maven io.netty:netty-codec-redis: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on io.netty:netty-codec-redis.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-5w86-c3rq-vjj7 (GitHub-reviewed advisory GHSA-5w86-c3rq-vjj7 lists affected ranges: Maven io.netty:netty-codec-redis >=4.2.0.Final =0 <=4.1.134.Final)

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