UBUNTU-CVE-2026-18355

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Source
https://ubuntu.com/security/CVE-2026-18355
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18355.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-18355
Upstream
  • CVE-2026-18355
Published
2026-09-07T15:17:00Z
Modified
2026-09-16T14:01:37Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

A heap buffer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). In sasl_io_start_packet(), the wrapped-record length read from the wire is validated only against an upper bound. A small wire length (0, 1, or 2) produces an encrypted_buffer_count below the already-consumed encrypted_buffer_offset, causing an unsigned subtraction underflow in sasl_io_read_packet(). PR_Recv is then requested to read approximately 4 GiB into a 1024-byte heap buffer, resulting in a heap buffer overflow with attacker-controlled content. After a successful SASL bind with integrity protection (SSF > 0), a remote authenticated attacker can cause a denial of service or potentially achieve remote code execution. This flaw is distinct from CVE-2026-11774, whose fix only guards against upper-bound overflow.

References

Affected packages

Ubuntu:22.04:LTS
389-ds-base

Package

Name
389-ds-base
Purl
pkg:deb/ubuntu/389-ds-base?arch=source&distro=jammy

Affected ranges

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

Affected versions

1.*
1.4.4.11-2build1
1.4.4.11-2build2
1.4.4.17-1
2.*
2.0.11-2
2.0.14-1
2.0.15-1
2.0.15-1ubuntu2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "389-ds",
            "binary_version": "2.0.15-1ubuntu2"
        },
        {
            "binary_name": "389-ds-base",
            "binary_version": "2.0.15-1ubuntu2"
        },
        {
            "binary_name": "389-ds-base-libs",
            "binary_version": "2.0.15-1ubuntu2"
        },
        {
            "binary_name": "cockpit-389-ds",
            "binary_version": "2.0.15-1ubuntu2"
        },
        {
            "binary_name": "python3-lib389",
            "binary_version": "2.0.15-1ubuntu2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18355.json"
Ubuntu:24.04:LTS
389-ds-base

Package

Name
389-ds-base
Purl
pkg:deb/ubuntu/389-ds-base?arch=source&distro=noble

Affected ranges

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

Affected versions

2.*
2.3.4+dfsg1-1
2.4.4+dfsg1-1ubuntu1
2.4.4+dfsg1-1ubuntu4
2.4.4+dfsg1-3
2.4.5+dfsg1-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "389-ds",
            "binary_version": "2.4.5+dfsg1-1"
        },
        {
            "binary_name": "389-ds-base",
            "binary_version": "2.4.5+dfsg1-1"
        },
        {
            "binary_name": "389-ds-base-libs",
            "binary_version": "2.4.5+dfsg1-1"
        },
        {
            "binary_name": "cockpit-389-ds",
            "binary_version": "2.4.5+dfsg1-1"
        },
        {
            "binary_name": "python3-lib389",
            "binary_version": "2.4.5+dfsg1-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18355.json"
Ubuntu:26.04:LTS
389-ds-base

Package

Name
389-ds-base
Purl
pkg:deb/ubuntu/389-ds-base?arch=source&distro=resolute

Affected ranges

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

Affected versions

3.*
3.1.2+dfsg1-1
3.1.2+vendor1-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "389-ds",
            "binary_version": "3.1.2+vendor1-2"
        },
        {
            "binary_name": "389-ds-base",
            "binary_version": "3.1.2+vendor1-2"
        },
        {
            "binary_name": "389-ds-base-libs",
            "binary_version": "3.1.2+vendor1-2"
        },
        {
            "binary_name": "cockpit-389-ds",
            "binary_version": "3.1.2+vendor1-2"
        },
        {
            "binary_name": "python3-lib389",
            "binary_version": "3.1.2+vendor1-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18355.json"
Ubuntu:Pro:16.04:LTS
389-ds-base

Package

Name
389-ds-base
Purl
pkg:deb/ubuntu/389-ds-base?arch=source&distro=esm-apps%2Fxenial

Affected ranges

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

Affected versions

1.*
1.3.3.12-1build1
1.3.3.13-1
1.3.4.5-2
1.3.4.8-1
1.3.4.8-3
1.3.4.8-3ubuntu1
1.3.4.8-4
1.3.4.9-1
1.3.4.9-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "389-ds",
            "binary_version": "1.3.4.9-1ubuntu0.1~esm1"
        },
        {
            "binary_name": "389-ds-base",
            "binary_version": "1.3.4.9-1ubuntu0.1~esm1"
        },
        {
            "binary_name": "389-ds-base-libs",
            "binary_version": "1.3.4.9-1ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18355.json"
Ubuntu:Pro:18.04:LTS
389-ds-base

Package

Name
389-ds-base
Purl
pkg:deb/ubuntu/389-ds-base?arch=source&distro=esm-apps%2Fbionic

Affected ranges

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

Affected versions

1.*
1.3.7.5-1
1.3.7.5-1build1
1.3.7.5-1build2
1.3.7.9-1
1.3.7.10-1
1.3.7.10-1ubuntu1
1.3.7.10-1ubuntu1+esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "389-ds",
            "binary_version": "1.3.7.10-1ubuntu1+esm1"
        },
        {
            "binary_name": "389-ds-base",
            "binary_version": "1.3.7.10-1ubuntu1+esm1"
        },
        {
            "binary_name": "389-ds-base-libs",
            "binary_version": "1.3.7.10-1ubuntu1+esm1"
        },
        {
            "binary_name": "python3-dirsrvtests",
            "binary_version": "1.3.7.10-1ubuntu1+esm1"
        },
        {
            "binary_name": "python3-lib389",
            "binary_version": "1.3.7.10-1ubuntu1+esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18355.json"
Ubuntu:Pro:20.04:LTS
389-ds-base

Package

Name
389-ds-base
Purl
pkg:deb/ubuntu/389-ds-base?arch=source&distro=esm-apps%2Ffocal

Affected ranges

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

Affected versions

1.*
1.4.1.6-4
1.4.1.6-4build1
1.4.2.4-1
1.4.2.4-1build1
1.4.3.2-1
1.4.3.2-1build1
1.4.3.6-2
1.4.3.6-2ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "389-ds",
            "binary_version": "1.4.3.6-2ubuntu0.1~esm1"
        },
        {
            "binary_name": "389-ds-base",
            "binary_version": "1.4.3.6-2ubuntu0.1~esm1"
        },
        {
            "binary_name": "389-ds-base-libs",
            "binary_version": "1.4.3.6-2ubuntu0.1~esm1"
        },
        {
            "binary_name": "cockpit-389-ds",
            "binary_version": "1.4.3.6-2ubuntu0.1~esm1"
        },
        {
            "binary_name": "python3-lib389",
            "binary_version": "1.4.3.6-2ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18355.json"