UBUNTU-CVE-2026-56766

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Source
https://ubuntu.com/security/CVE-2026-56766
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56766.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-56766
Upstream
Published
2026-06-25T19:16:00Z
Modified
2026-06-29T23:19:15.192995452Z
Severity
  • 8.8 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H CVSS Calculator
  • 8.6 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Hydra through 9.7, fixed in commit 9cc84c2, contains a stack buffer overflow in NTLM authentication across SMTP, POP3, IMAP, NNTP, HTTP, HTTP-Proxy, and HTTP-Proxy-Urlenum modules when processing malicious NTLM Type-2 challenges. A malicious server can send a crafted NTLM Type-2 challenge with an excessively long domain string, causing base64-encoded response data to overflow a 500-byte stack buffer by 18 to 330 bytes, enabling remote code execution on systems without stack protection.

References

Affected packages

Ubuntu:16.04:LTS
hydra

Package

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

Affected ranges

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

Affected versions

8.*
8.1-1
8.1-1build1
8.1-1build2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "hydra",
            "binary_version": "8.1-1build2"
        },
        {
            "binary_name": "hydra-gtk",
            "binary_version": "8.1-1build2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56766.json"
Ubuntu:18.04:LTS
hydra

Package

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

Affected ranges

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

Affected versions

8.*
8.6-1
8.6-1build1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "hydra",
            "binary_version": "8.6-1build1"
        },
        {
            "binary_name": "hydra-gtk",
            "binary_version": "8.6-1build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56766.json"
Ubuntu:20.04:LTS
hydra

Package

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

Affected ranges

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

Affected versions

9.*
9.0-1build1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "hydra",
            "binary_version": "9.0-1build1"
        },
        {
            "binary_name": "hydra-gtk",
            "binary_version": "9.0-1build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56766.json"
Ubuntu:22.04:LTS
hydra

Package

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

Affected ranges

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

Affected versions

9.*
9.1-1
9.2-1
9.2-1ubuntu1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "hydra",
            "binary_version": "9.2-1ubuntu1"
        },
        {
            "binary_name": "hydra-gtk",
            "binary_version": "9.2-1ubuntu1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56766.json"
Ubuntu:24.04:LTS
hydra

Package

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

Affected ranges

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

Affected versions

9.*
9.5-1
9.5-1build1
9.5-1build3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "hydra",
            "binary_version": "9.5-1build3"
        },
        {
            "binary_name": "hydra-gtk",
            "binary_version": "9.5-1build3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56766.json"
Ubuntu:25.10
hydra

Package

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

Affected ranges

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

Affected versions

9.*
9.5-3build1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "hydra",
            "binary_version": "9.5-3build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56766.json"
Ubuntu:26.04:LTS
hydra

Package

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

Affected ranges

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

Affected versions

9.*
9.5-3build1
9.6-3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "hydra",
            "binary_version": "9.6-3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56766.json"