CVE-2026-56821
Fixed in a distro release EPSS <1%CVSS 7.4
Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, the OcspServerCertificateValidator flags an out-of-date OCSP response but does not stop processing it, so an expired GOOD response is still reported as VALID, letting an on-path attacker replay a stale GOOD response to bypass revocation of a since-revoked certificate. Exploitation can lead to certificate revocation bypass via replay of an expired OCSP response. Any application using OcspServerCertificateValidator is affected; a revoked certificate can be accepted. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.
Products: netty
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| Maven | io.netty:netty-handler-ssl-ocsp | 4.2.16.Final |
| Maven | io.netty:netty-handler-ssl-ocsp | 4.1.136.Final |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Chainguard | apache-hop | 2.18.1-r7 |
| Chainguard | apache-hop-fips | 2.18.1-r5 |
| Chainguard | cassandra-5.0 | 5.0.8-r12 |
| Chainguard | cassandra-fips-5.0 | 5.0.8-r7 |
| Chainguard | gremlin-server | 3.8.1-r2 |
| Chainguard | hadoop-3.5 | no fix |
| Chainguard | hadoop-fips-3.3.6 | no fix |
| Chainguard | hadoop-fips-3.4.2 | no fix |
| Chainguard | hadoop-fips-3.5 | 3.5.0-r3 |
| Chainguard | hadoop-fips-3.5 | no fix |
| Chainguard | management-api-for-apache-cassandra-5.0 | 0.1.122-r2 |
| Chainguard | pinot | 1.5.1-r3 |
| Chainguard | pinot-fips | 1.5.1-r3 |
| Chainguard | ranger | no fix |
| Chainguard | seata-server | 2.6.0-r22 |
| Chainguard | tez | 0.10.5-r21 |
| Chainguard | thingsboard-tb-mqtt-transport | 4.3.1.3-r6 |
| Chainguard | thingsboard-tb-node | 4.3.1.3-r6 |
| Debian 12 | netty | no fix |
| Debian 13 | netty | no fix |
| Debian 14 | netty | no fix |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | netty-tcnative | 2.0.80-150200.3.48.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | netty-tcnative | 2.0.80-150200.3.48.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | netty-tcnative | 2.0.80-150200.3.48.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | netty-tcnative | 2.0.80-150200.3.48.1 |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | netty-tcnative | 2.0.80-150200.3.48.1 |
| SUSE Linux Enterprise Module for Package Hub 15 SP7 | netty | 4.1.136-150200.4.53.1 |
| SUSE Linux Enterprise Server 15 SP4-LTSS | netty-tcnative | 2.0.80-150200.3.48.1 |
| SUSE Linux Enterprise Server 15 SP5-LTSS | netty-tcnative | 2.0.80-150200.3.48.1 |
| SUSE Linux Enterprise Server 15 SP6-LTSS | netty-tcnative | 2.0.80-150200.3.48.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | netty-tcnative | 2.0.80-150200.3.48.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | netty-tcnative | 2.0.80-150200.3.48.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | netty-tcnative | 2.0.80-150200.3.48.1 |
| Ubuntu 26.10 | netty | no fix |
| Ubuntu Pro 14.04 LTS | netty | no fix |
| Ubuntu Pro 16.04 LTS | netty | no fix |
| Ubuntu Pro 18.04 LTS | netty | no fix |
| Ubuntu Pro 20.04 LTS | netty | no fix |
| Ubuntu Pro 22.04 LTS | netty | no fix |
| Ubuntu Pro 24.04 LTS | netty | no fix |
| Ubuntu Pro 26.04 LTS | netty | no fix |
| Wolfi | cassandra-5.0 | 5.0.8-r12 |
| Wolfi | management-api-for-apache-cassandra-5.0 | 0.1.122-r2 |
| Wolfi | tez | 0.10.5-r21 |
| Wolfi | thingsboard-tb-mqtt-transport | 4.3.1.3-r6 |
| Wolfi | thingsboard-tb-node | 4.3.1.3-r6 |
| openSUSE Tumbleweed | netty | 4.1.136-1.1 |