CVE-2026-56818
Description
Netty is an asynchronous, event-driven network application framework. Prior to 4.1.136.Final and 4.2.16.Final, the RedisArrayAggregator Redis codec clears retained partial aggregate state when the maxNestedArrayDepth limit is exceeded, but it does not clear the same state when the sibling maxElements limit is exceeded. A peer can start a valid RESP array, send a bulk string child, then send a nested array header longer than the configured maxElements. Netty throws a decoder exception in decodeRedisArrayHeader, but the existing partial aggregate remains retained in the handler. If the application leaves the channel alive after the exception, later messages are still consumed into the pre-error aggregate, allowing an unauthenticated peer to keep attacker-controlled aggregate state alive across a security-limit exception and pin retained pooled buffers. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Mitigation details
CVE-2026-56818 NameCVE-2026-56818 SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) Vulnerable and fixed packages The table below lists information on source packages. Source PackageReleaseVersionStatus netty (PTS)bullseye1:4.1.48-4+deb11u2vulnerable bullseye…
CVE-2026-56818
| Name | CVE-2026-56818 |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| netty (PTS) | bullseye | 1:4.1.48-4+deb11u2 | vulnerable |
| bullseye (security) | 1:4.1.48-4+deb11u3 | vulnerable | |
| bookworm, bookworm (security) | 1:4.1.48-7+deb12u2 | vulnerable | |
| trixie (security), trixie | 1:4.1.48-10+deb13u1 | vulnerable | |
| forky, sid | 1:4.1.48-16 | vulnerable |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| netty | source | (unstable) | (unfixed) |
Notes
https://bugzilla.redhat.com/show_bug.cgi?id=2507476
check missing upstream GHSA
Apply commands
https://bugzilla.redhat.com/show_bug.cgi?id=2507476check missing upstream GHSAOS impact
Debian Affected 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Affected | — |
| forky | Affected | — |
| bullseye | Affected | — |
| bookworm | Affected | — |
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
References
- https://security-tracker.debian.org/tracker/CVE-2026-56818
- https://www.suse.com/security/cve/CVE-2026-56818.html
- https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b
- https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6
- https://github.com/netty/netty/pull/17065
- https://github.com/netty/netty/security/advisories/GHSA-p9jm-q85p-7mcp
CWEs
CWE-401 CWE-703
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.