UBUNTU-CVE-2026-56821

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Source

https://ubuntu.com/security/CVE-2026-56821

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56821.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-56821

Upstream

CVE-2026-56821

Published

2026-07-29T00:16:00Z

Modified

2026-09-10T16:30:28Z

Severity

7.4 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

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 Prior to versions 4.1.136.Final and 4.2.16.Final, the OcspServerCertificateValidator flags an out-of-date OCSP response but does not stop processing it, so an expired GOOD response is still reported as VALID, letting an on-path attacker replay a stale GOOD response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.

References

Affected packages

Ubuntu:Pro:14.04:LTS

netty

Package

Name: netty
Purl: pkg:deb/ubuntu/netty?arch=source&distro=esm-infra-legacy%2Ftrusty

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1:3.*

1:3.2.6.Final-2

1:3.2.6.Final-2+deb8u2build0.14.04.1~esm1

1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libnetty-java",
            "binary_version": "1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56821.json"

Ubuntu:Pro:16.04:LTS

netty

Package

Name: netty
Purl: pkg:deb/ubuntu/netty?arch=source&distro=esm-apps-legacy%2Fxenial

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1:3.*

1:3.2.6.Final-2

1:4.*

1:4.0.32-1

1:4.0.33-1

1:4.0.34-1

1:4.0.34-1ubuntu0.1~esm1

1:4.0.34-1ubuntu0.1~esm2

1:4.0.34-1ubuntu0.1~esm3

1:4.0.34-1ubuntu0.1~esm4

1:4.0.34-1ubuntu0.1~esm5

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.0.34-1ubuntu0.1~esm5"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56821.json"

Ubuntu:Pro:18.04:LTS

netty

Package

Name: netty
Purl: pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fbionic

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1:4.*

1:4.1.7-4

1:4.1.7-4ubuntu0.1~esm1

1:4.1.7-4ubuntu0.1

1:4.1.7-4ubuntu0.1+esm1

1:4.1.7-4ubuntu0.1+esm2

1:4.1.7-4ubuntu0.1+esm3

1:4.1.7-4ubuntu0.1+esm4

1:4.1.7-4ubuntu0.1+esm5

1:4.1.7-4ubuntu0.1+esm6

1:4.1.7-4ubuntu0.1+esm7

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.1.7-4ubuntu0.1+esm7"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56821.json"

Ubuntu:Pro:20.04:LTS

netty

Package

Name: netty
Purl: pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Ffocal

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1:4.*

1:4.1.33-1

1:4.1.33-2

1:4.1.33-3

1:4.1.45-1

1:4.1.45-1ubuntu0.1~esm1

1:4.1.45-1ubuntu0.1~esm2

1:4.1.45-1ubuntu0.1~esm3

1:4.1.45-1ubuntu0.1~esm4

1:4.1.45-1ubuntu0.1~esm6

1:4.1.45-1ubuntu0.1~esm7

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.1.45-1ubuntu0.1~esm7"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56821.json"

Ubuntu:Pro:22.04:LTS

netty

Package

Name: netty
Purl: pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fjammy

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1:4.*

1:4.1.48-4

1:4.1.48-4+deb11u1build0.22.04.1

1:4.1.48-4+deb11u2build0.22.04.1

1:4.1.48-4+deb11u2ubuntu0.1~esm1

1:4.1.48-4+deb11u2ubuntu0.1~esm2

1:4.1.48-4+deb11u2ubuntu0.1

1:4.1.48-4+deb11u2ubuntu0.1+esm1

1:4.1.48-4+deb11u2ubuntu0.1+esm3

1:4.1.48-4+deb11u2ubuntu0.2

1:4.1.48-4+deb11u2ubuntu0.2+esm1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.1.48-4+deb11u2ubuntu0.2+esm1"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56821.json"

Ubuntu:Pro:24.04:LTS

netty

Package

Name: netty
Purl: pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fnoble

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1:4.*

1:4.1.48-7

1:4.1.48-8

1:4.1.48-9

1:4.1.48-9ubuntu0.1~esm1

1:4.1.48-9ubuntu0.1~esm2

1:4.1.48-9ubuntu0.1

1:4.1.48-9ubuntu0.1+esm1

1:4.1.48-9ubuntu0.1+esm3

1:4.1.48-9ubuntu0.2

1:4.1.48-9ubuntu0.2+esm1

1:4.1.48-9ubuntu0.2+esm2

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.1.48-9ubuntu0.2+esm2"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56821.json"

Ubuntu:Pro:26.04:LTS

netty

Package

Name: netty
Purl: pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fresolute

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

1:4.*

1:4.1.48-10

1:4.1.48-11

1:4.1.48-12

1:4.1.48-13

1:4.1.48-14

1:4.1.48-16

1:4.1.48-16ubuntu0.1~esm2

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libnetty-buffer-java",
            "binary_version": "1:4.1.48-16ubuntu0.1~esm2"
        },
        {
            "binary_name": "libnetty-common-java",
            "binary_version": "1:4.1.48-16ubuntu0.1~esm2"
        },
        {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.1.48-16ubuntu0.1~esm2"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56821.json"