UBUNTU-CVE-2026-63388

See a problem?
Please try reporting it to the source first.
Source
https://ubuntu.com/security/CVE-2026-63388
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63388.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-63388
Upstream
Downstream
Related
Published
2026-08-20T18:16:00Z
Modified
2026-09-29T23:41:58Z
Severity
  • 8.4 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a heap out-of-bounds write in bufferevent_sock.c when bufferevent_socket_set_conn_address_ copies a kernel-supplied AF_UNIX peer address into bufferevent_private.conn_address. Release builds compiled with NDEBUG disable the EVUTIL_ASSERT length guard, and the evhttp accept path can pass a 110-byte sockaddr from accept() into the 28-byte field. An unauthenticated local peer able to connect to an AF_UNIX listener can overwrite the adjacent dns_request pointer and heap data, causing memory corruption with confidentiality, integrity, and availability impact. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

References

Affected packages

Ubuntu:Pro:18.04:LTS / libevent

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.1.8-stable-4ubuntu0.1~esm2

Affected versions

2.*
2.1.8-stable-4
2.1.8-stable-4build1
2.1.8-stable-4ubuntu0.1~esm1

Ecosystem specific 

{
    "availability":  "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
    "binaries":  [
        {
            "binary_name":  "libevent-2.1-6",
            "binary_version":  "2.1.8-stable-4ubuntu0.1~esm2"
        },
        {
            "binary_name":  "libevent-core-2.1-6",
            "binary_version":  "2.1.8-stable-4ubuntu0.1~esm2"
        },
        {
            "binary_name":  "libevent-extra-2.1-6",
            "binary_version":  "2.1.8-stable-4ubuntu0.1~esm2"
        },
        {
            "binary_name":  "libevent-openssl-2.1-6",
            "binary_version":  "2.1.8-stable-4ubuntu0.1~esm2"
        },
        {
            "binary_name":  "libevent-pthreads-2.1-6",
            "binary_version":  "2.1.8-stable-4ubuntu0.1~esm2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63388.json"

Ubuntu:Pro:20.04:LTS / libevent

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.1.11-stable-1ubuntu0.1~esm2

Affected versions

2.*
2.1.8-stable-4build1
2.1.11-stable-1~exp0
2.1.11-stable-1
2.1.11-stable-1ubuntu0.1~esm1

Ecosystem specific 

{
    "availability":  "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
    "binaries":  [
        {
            "binary_name":  "libevent-2.1-7",
            "binary_version":  "2.1.11-stable-1ubuntu0.1~esm2"
        },
        {
            "binary_name":  "libevent-core-2.1-7",
            "binary_version":  "2.1.11-stable-1ubuntu0.1~esm2"
        },
        {
            "binary_name":  "libevent-extra-2.1-7",
            "binary_version":  "2.1.11-stable-1ubuntu0.1~esm2"
        },
        {
            "binary_name":  "libevent-openssl-2.1-7",
            "binary_version":  "2.1.11-stable-1ubuntu0.1~esm2"
        },
        {
            "binary_name":  "libevent-pthreads-2.1-7",
            "binary_version":  "2.1.11-stable-1ubuntu0.1~esm2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63388.json"

Ubuntu:22.04:LTS / libevent

Package

Name
libevent
Purl
pkg:deb/ubuntu/libevent?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.1.12-stable-1ubuntu0.2

Affected versions

2.*
2.1.12-stable-1
2.1.12-stable-1build1
2.1.12-stable-1build2
2.1.12-stable-1build3
2.1.12-stable-1ubuntu0.1

Ecosystem specific 

{
    "availability":  "No subscription required",
    "binaries":  [
        {
            "binary_name":  "libevent-2.1-7",
            "binary_version":  "2.1.12-stable-1ubuntu0.2"
        },
        {
            "binary_name":  "libevent-core-2.1-7",
            "binary_version":  "2.1.12-stable-1ubuntu0.2"
        },
        {
            "binary_name":  "libevent-extra-2.1-7",
            "binary_version":  "2.1.12-stable-1ubuntu0.2"
        },
        {
            "binary_name":  "libevent-openssl-2.1-7",
            "binary_version":  "2.1.12-stable-1ubuntu0.2"
        },
        {
            "binary_name":  "libevent-pthreads-2.1-7",
            "binary_version":  "2.1.12-stable-1ubuntu0.2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63388.json"

Ubuntu:24.04:LTS / libevent

Package

Name
libevent
Purl
pkg:deb/ubuntu/libevent?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.1.12-stable-9ubuntu2.2

Affected versions

2.*
2.1.12-stable-9
2.1.12-stable-9ubuntu2
2.1.12-stable-9ubuntu2.1

Ecosystem specific 

{
    "availability":  "No subscription required",
    "binaries":  [
        {
            "binary_name":  "libevent-2.1-7t64",
            "binary_version":  "2.1.12-stable-9ubuntu2.2"
        },
        {
            "binary_name":  "libevent-core-2.1-7t64",
            "binary_version":  "2.1.12-stable-9ubuntu2.2"
        },
        {
            "binary_name":  "libevent-extra-2.1-7t64",
            "binary_version":  "2.1.12-stable-9ubuntu2.2"
        },
        {
            "binary_name":  "libevent-openssl-2.1-7t64",
            "binary_version":  "2.1.12-stable-9ubuntu2.2"
        },
        {
            "binary_name":  "libevent-pthreads-2.1-7t64",
            "binary_version":  "2.1.12-stable-9ubuntu2.2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63388.json"

Ubuntu:26.04:LTS / libevent

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.1.12-stable-10ubuntu0.2

Affected versions

2.*
2.1.12-stable-10build1
2.1.12-stable-10build2
2.1.12-stable-10ubuntu0.1

Ecosystem specific 

{
    "availability":  "No subscription required",
    "binaries":  [
        {
            "binary_name":  "libevent-2.1-7t64",
            "binary_version":  "2.1.12-stable-10ubuntu0.2"
        },
        {
            "binary_name":  "libevent-core-2.1-7t64",
            "binary_version":  "2.1.12-stable-10ubuntu0.2"
        },
        {
            "binary_name":  "libevent-extra-2.1-7t64",
            "binary_version":  "2.1.12-stable-10ubuntu0.2"
        },
        {
            "binary_name":  "libevent-openssl-2.1-7t64",
            "binary_version":  "2.1.12-stable-10ubuntu0.2"
        },
        {
            "binary_name":  "libevent-pthreads-2.1-7t64",
            "binary_version":  "2.1.12-stable-10ubuntu0.2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63388.json"