UBUNTU-CVE-2026-18798

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Source
https://ubuntu.com/security/CVE-2026-18798
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18798.json
JSON Data
https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2026-18798
Upstream
Downstream
Related
Published
2026-08-25T00:00:00Z
Modified
2026-09-02T19:36:26Z
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
  • Ubuntu - medium
Summary
[none]
Details

Issue summary: QUIC server may double free QRX (QUIC record layer RX) object when channel creation fails for initial packet. Impact summary: Double free leads to heap corruption, which typically results in termination of QUIC server process, leading to Denial of Service. There is so far no evidence that this double free is exploitable for remote code execution, thus it is considered highly improbable. CWE: CWE-415: Double Free Description: In order to validate initial packet, OpenSSL QUIC stack default packet handler (port_default_packet_handler()) creates a so-called QRX object. If the initial packet validates successfully with QRX object, the default packet handler proceeds to channel (connection object) creation. The QRX object used for packet validation is passed to port_bind_channel(), so it becomes part of the newly created connection. If port_bind_channel() fails, then it also frees the QRX object. Once port_bind_channel() returns, the port_default_packet_handler() detects the failure and proceeds to the error branch, where the same QRX object is freed for the second time. The failure in port_bind_channel() function can be induced with a relatively low effort by a malformed (non RFC 9000 compliant) INITIAL packet. If the packet carries DCID (destination connection ID) which is shorter than 8 bytes, then port_bind_channel() jumps to the error path after ossl_quic_lcidm_enrol_odcid() detects that the DCID has invalid length. FIPS impact: no The FIPS module is not affected, as the QUIC implementation is outside of the OpenSSL FIPS module boundary.

References

Affected packages

Ubuntu:26.04:LTS
edk2

Package

Name
edk2
Purl
pkg:deb/ubuntu/edk2?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

2025.*
2025.02-8ubuntu3
2025.11-3ubuntu6
2025.11-3ubuntu7

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "efi-shell-aa64",
            "binary_version": "2025.11-3ubuntu7"
        },
        {
            "binary_name": "efi-shell-loongarch64",
            "binary_version": "2025.11-3ubuntu7"
        },
        {
            "binary_name": "efi-shell-riscv64",
            "binary_version": "2025.11-3ubuntu7"
        },
        {
            "binary_name": "efi-shell-x64",
            "binary_version": "2025.11-3ubuntu7"
        },
        {
            "binary_name": "ovmf",
            "binary_version": "2025.11-3ubuntu7"
        },
        {
            "binary_name": "ovmf-amdsev",
            "binary_version": "2025.11-3ubuntu7"
        },
        {
            "binary_name": "ovmf-generic",
            "binary_version": "2025.11-3ubuntu7"
        },
        {
            "binary_name": "ovmf-inteltdx",
            "binary_version": "2025.11-3ubuntu7"
        },
        {
            "binary_name": "ovmf-legacy",
            "binary_version": "2025.11-3ubuntu7"
        },
        {
            "binary_name": "qemu-efi-aarch64",
            "binary_version": "2025.11-3ubuntu7"
        },
        {
            "binary_name": "qemu-efi-loongarch64",
            "binary_version": "2025.11-3ubuntu7"
        },
        {
            "binary_name": "qemu-efi-riscv64",
            "binary_version": "2025.11-3ubuntu7"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18798.json"
edk2-hwe

Package

Name
edk2-hwe
Purl
pkg:deb/ubuntu/edk2-hwe?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

2025.*
2025.11-3ubuntu6
2025.11-3ubuntu8

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "efi-shell-aa64-hwe",
            "binary_version": "2025.11-3ubuntu8"
        },
        {
            "binary_name": "efi-shell-loongarch64-hwe",
            "binary_version": "2025.11-3ubuntu8"
        },
        {
            "binary_name": "efi-shell-riscv64-hwe",
            "binary_version": "2025.11-3ubuntu8"
        },
        {
            "binary_name": "efi-shell-x64-hwe",
            "binary_version": "2025.11-3ubuntu8"
        },
        {
            "binary_name": "ovmf-amdsev-hwe",
            "binary_version": "2025.11-3ubuntu8"
        },
        {
            "binary_name": "ovmf-generic-hwe",
            "binary_version": "2025.11-3ubuntu8"
        },
        {
            "binary_name": "ovmf-hwe",
            "binary_version": "2025.11-3ubuntu8"
        },
        {
            "binary_name": "ovmf-inteltdx-hwe",
            "binary_version": "2025.11-3ubuntu8"
        },
        {
            "binary_name": "ovmf-legacy-hwe",
            "binary_version": "2025.11-3ubuntu8"
        },
        {
            "binary_name": "qemu-efi-aarch64-hwe",
            "binary_version": "2025.11-3ubuntu8"
        },
        {
            "binary_name": "qemu-efi-loongarch64-hwe",
            "binary_version": "2025.11-3ubuntu8"
        },
        {
            "binary_name": "qemu-efi-riscv64-hwe",
            "binary_version": "2025.11-3ubuntu8"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18798.json"
openssl

Package

Name
openssl
Purl
pkg:deb/ubuntu/openssl?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
3.5.5-1ubuntu3.4

Affected versions

3.*
3.5.3-1ubuntu2
3.5.5-1ubuntu1
3.5.5-1ubuntu3
3.5.5-1ubuntu3.2
3.5.5-1ubuntu3.3

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "libssl3t64",
            "binary_version": "3.5.5-1ubuntu3.4"
        },
        {
            "binary_name": "openssl",
            "binary_version": "3.5.5-1ubuntu3.4"
        },
        {
            "binary_name": "openssl-provider-legacy",
            "binary_version": "3.5.5-1ubuntu3.4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18798.json"
Ubuntu:Pro:16.04:LTS
nodejs

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.10.25~dfsg2-2ubuntu1
4.*
4.2.2~dfsg-1
4.2.3~dfsg-1
4.2.4~dfsg-1ubuntu1
4.2.4~dfsg-2
4.2.6~dfsg-1ubuntu1
4.2.6~dfsg-1ubuntu4
4.2.6~dfsg-1ubuntu4.1
4.2.6~dfsg-1ubuntu4.2
4.2.6~dfsg-1ubuntu4.2+esm1
4.2.6~dfsg-1ubuntu4.2+esm2
4.2.6~dfsg-1ubuntu4.2+esm3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "nodejs",
            "binary_version": "4.2.6~dfsg-1ubuntu4.2+esm3"
        },
        {
            "binary_name": "nodejs-legacy",
            "binary_version": "4.2.6~dfsg-1ubuntu4.2+esm3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18798.json"
Ubuntu:Pro:18.04:LTS
nodejs

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

6.*
6.11.4~dfsg-1ubuntu1
6.11.4~dfsg-1ubuntu2
6.12.0~dfsg-1ubuntu1
6.12.0~dfsg-2ubuntu1
6.12.0~dfsg-2ubuntu2
8.*
8.10.0~dfsg-2
8.10.0~dfsg-2ubuntu0.2
8.10.0~dfsg-2ubuntu0.3
8.10.0~dfsg-2ubuntu0.4
8.10.0~dfsg-2ubuntu0.4+esm1
8.10.0~dfsg-2ubuntu0.4+esm2
8.10.0~dfsg-2ubuntu0.4+esm3
8.10.0~dfsg-2ubuntu0.4+esm4
8.10.0~dfsg-2ubuntu0.4+esm5
8.10.0~dfsg-2ubuntu0.4+esm6

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "nodejs",
            "binary_version": "8.10.0~dfsg-2ubuntu0.4+esm6"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18798.json"
Ubuntu:Pro:FIPS-preview:22.04:LTS
openssl-fips

Package

Name
openssl-fips
Purl
pkg:deb/ubuntu/openssl-fips?arch=source&distro=fips-preview%2Fjammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.0.5-0ubuntu0.1+Fips2.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "openssl-fips-module-3",
            "binary_version": "3.0.5-0ubuntu0.1+Fips2.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18798.json"
Ubuntu:Pro:FIPS-updates:22.04:LTS
openssl-fips

Package

Name
openssl-fips
Purl
pkg:deb/ubuntu/openssl-fips?arch=source&distro=fips-updates%2Fjammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.0.5-0ubuntu0.1+Fips2.1
3.0.5-0ubuntu0.2+Fips1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "openssl-fips-module-3",
            "binary_version": "3.0.5-0ubuntu0.2+Fips1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18798.json"
Ubuntu:Pro:FIPS-updates:24.04:LTS
openssl-fips

Package

Name
openssl-fips
Purl
pkg:deb/ubuntu/openssl-fips?arch=source&distro=fips-updates%2Fnoble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.0.13-0ubuntu3+Fips1
3.0.13-0ubuntu3.6+Fips1
3.0.13-0ubuntu3.12+Fips1
3.0.13-0ubuntu3.15+Fips1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "openssl-fips-module-3",
            "binary_version": "3.0.13-0ubuntu3.15+Fips1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18798.json"