UBUNTU-CVE-2026-10645

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Source
https://ubuntu.com/security/CVE-2026-10645
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-10645.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-10645
Upstream
  • CVE-2026-10645
Published
2026-06-23T01:16:00Z
Modified
2026-06-24T08:58:46Z
Severity
  • 4.9 (Medium) CVSS_V3 - CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Zephyr's ext2 directory-entry parser does not fully validate on-disk directory entry structure before copying the entry name and advancing traversal state. In ext2fetchdirentry() (subsys/fs/ext2/ext2diskops.c), the code only checks denamelen <= EXT2MAXFILENAME and then copies the name with memcpy without validating the structural relationship between dereclen, denamelen, and the directory block boundary (for example that dereclen is non-zero, at least the size of the entry header, and that the record fits within the block). Callers such as finddirentry() and ext2getdirentry() (subsys/fs/ext2/ext2impl.c) then advance traversal using the unvalidated dereclen. A crafted ext2 image can therefore cause an out-of-bounds read from the directory block buffer when a malformed entry near the end of a block triggers an oversized name copy, or a zero-progress infinite loop when derec_len == 0. The issue is not reached at mount time but later through directory traversal paths such as pathname lookup, stat/open/unlink/rename, and readdir. The primary impact is denial of service and out-of-bounds reads under attacker-controlled ext2 images mounted from untrusted media.

References

Affected packages

Ubuntu:16.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=xenial

Affected ranges

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

Affected versions

3.*
3.1.2-1
3.1.2-1build1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libzephyr4",
            "binary_version": "3.1.2-1build1"
        },
        {
            "binary_name": "libzephyr4-krb5",
            "binary_version": "3.1.2-1build1"
        },
        {
            "binary_name": "zephyr-clients",
            "binary_version": "3.1.2-1build1"
        },
        {
            "binary_name": "zephyr-server",
            "binary_version": "3.1.2-1build1"
        },
        {
            "binary_name": "zephyr-server-krb5",
            "binary_version": "3.1.2-1build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-10645.json"
Ubuntu:18.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=bionic

Affected ranges

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

Affected versions

3.*
3.1.2-1build1
3.1.2-1build2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libzephyr4",
            "binary_version": "3.1.2-1build2"
        },
        {
            "binary_name": "libzephyr4-krb5",
            "binary_version": "3.1.2-1build2"
        },
        {
            "binary_name": "zephyr-clients",
            "binary_version": "3.1.2-1build2"
        },
        {
            "binary_name": "zephyr-server",
            "binary_version": "3.1.2-1build2"
        },
        {
            "binary_name": "zephyr-server-krb5",
            "binary_version": "3.1.2-1build2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-10645.json"
Ubuntu:20.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=focal

Affected ranges

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

Affected versions

3.*
3.1.2-1build3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libzephyr4",
            "binary_version": "3.1.2-1build3"
        },
        {
            "binary_name": "libzephyr4-krb5",
            "binary_version": "3.1.2-1build3"
        },
        {
            "binary_name": "zephyr-clients",
            "binary_version": "3.1.2-1build3"
        },
        {
            "binary_name": "zephyr-server",
            "binary_version": "3.1.2-1build3"
        },
        {
            "binary_name": "zephyr-server-krb5",
            "binary_version": "3.1.2-1build3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-10645.json"
Ubuntu:22.04:LTS
zephyr

Package

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

Affected ranges

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

Affected versions

3.*
3.1.2-1build3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libzephyr4",
            "binary_version": "3.1.2-1build3"
        },
        {
            "binary_name": "libzephyr4-krb5",
            "binary_version": "3.1.2-1build3"
        },
        {
            "binary_name": "zephyr-clients",
            "binary_version": "3.1.2-1build3"
        },
        {
            "binary_name": "zephyr-server",
            "binary_version": "3.1.2-1build3"
        },
        {
            "binary_name": "zephyr-server-krb5",
            "binary_version": "3.1.2-1build3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-10645.json"
Ubuntu:24.04:LTS
zephyr

Package

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

Affected ranges

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

Affected versions

3.*
3.1.2-1.1
3.1.2-1.1build1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libzephyr4",
            "binary_version": "3.1.2-1.1build1"
        },
        {
            "binary_name": "libzephyr4-krb5",
            "binary_version": "3.1.2-1.1build1"
        },
        {
            "binary_name": "zephyr-clients",
            "binary_version": "3.1.2-1.1build1"
        },
        {
            "binary_name": "zephyr-server",
            "binary_version": "3.1.2-1.1build1"
        },
        {
            "binary_name": "zephyr-server-krb5",
            "binary_version": "3.1.2-1.1build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-10645.json"
Ubuntu:25.10
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=questing

Affected ranges

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

Affected versions

3.*
3.1.2-1.1build1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libzephyr4",
            "binary_version": "3.1.2-1.1build1"
        },
        {
            "binary_name": "libzephyr4-krb5",
            "binary_version": "3.1.2-1.1build1"
        },
        {
            "binary_name": "zephyr-clients",
            "binary_version": "3.1.2-1.1build1"
        },
        {
            "binary_name": "zephyr-server",
            "binary_version": "3.1.2-1.1build1"
        },
        {
            "binary_name": "zephyr-server-krb5",
            "binary_version": "3.1.2-1.1build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-10645.json"
Ubuntu:26.04:LTS
zephyr

Package

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

Affected ranges

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

Affected versions

3.*
3.1.2-1.1build1
3.1.2-4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libzephyr4",
            "binary_version": "3.1.2-4"
        },
        {
            "binary_name": "libzephyr4-krb5",
            "binary_version": "3.1.2-4"
        },
        {
            "binary_name": "zephyr-clients",
            "binary_version": "3.1.2-4"
        },
        {
            "binary_name": "zephyr-server",
            "binary_version": "3.1.2-4"
        },
        {
            "binary_name": "zephyr-server-krb5",
            "binary_version": "3.1.2-4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-10645.json"