UBUNTU-CVE-2026-100661

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Source
https://ubuntu.com/security/CVE-2026-100661
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100661.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-100661
Upstream
Published
2026-09-29T00:00:00Z
Modified
2026-09-29T23:41:44Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • 8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Netty's HTTP/3 codec (io.netty:netty-codec-http3) versions 4.2.0.Final through 4.2.17.Final contain a denial-of-service vulnerability in the QPACK prefixed-integer decoder (QpackUtil.decodePrefixedInteger), which does not bound the number of continuation bytes it will process. A remote, unauthenticated peer can open a QPACK unidirectional stream (type 0x02 encoder or 0x03 decoder) and send a first byte with all prefix bits set (e.g. 0xFF for a 7-bit prefix or 0x3F for a 5-bit prefix) followed by an endless run of 0x80 continuation bytes. The decoder returns -1 ('need more bytes'), so callers never consume the input, the ByteToMessageDecoder cumulator grows without bound, and each decode() invocation re-scans the whole accumulated buffer, yielding O(N^2) CPU cost. The result is unbounded per-connection heap growth (OutOfMemoryError) and event-loop CPU starvation, reachable in every configuration. Fixed in 4.2.18.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-2026-100661.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-2026-100661.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-2026-100661.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-2026-100661.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-2026-100661.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-2026-100661.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-2026-100661.json"