UBUNTU-CVE-2026-55766

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Source
https://ubuntu.com/security/CVE-2026-55766
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55766.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-55766
Upstream
Published
2026-06-23T16:17:00Z
Modified
2026-06-25T19:19:15.915628177Z
Severity
  • 4.8 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

guzzlehttp/psr7 is a PSR-7 HTTP message library implementation in PHP. Prior to 2.12.1, guzzlehttp/psr7 did not reject CR/LF characters in certain first-party HTTP start-line fields: the request method, protocol version, and response reason phrase. If an application placed attacker-controlled data into one of those fields and later serialized the PSR-7 message as raw HTTP/1.x, for example with Message::toString() or an equivalent serializer, the serialized message could contain attacker-controlled header lines. The issue can also be reached through Message::parseRequest() or Message::parseResponse() when malformed raw messages are parsed into first-party PSR-7 objects and then serialized again. Creating or modifying a Request, Response, or other PSR-7 object alone is not sufficient. The issue requires the malformed message to be serialized and written to the network, forwarded, replayed, or otherwise processed by software that does not independently reject the malformed start line. This vulnerability is fixed in 2.12.1.

References

Affected packages

Ubuntu:16.04:LTS
php-guzzlehttp-psr7

Package

Name
php-guzzlehttp-psr7
Purl
pkg:deb/ubuntu/php-guzzlehttp-psr7?arch=source&distro=xenial

Affected ranges

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

Affected versions

1.*
1.1.0-1
1.2.0-1
1.2.1-1
1.2.2-1
1.2.2-1build1
1.2.2-1ubuntu1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "php-guzzlehttp-psr7",
            "binary_version": "1.2.2-1ubuntu1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55766.json"
Ubuntu:20.04:LTS
php-guzzlehttp-psr7

Package

Name
php-guzzlehttp-psr7
Purl
pkg:deb/ubuntu/php-guzzlehttp-psr7?arch=source&distro=focal

Affected ranges

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

Affected versions

1.*
1.4.2-0.1
1.4.2-0.1+deb10u2build0.20.04.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "php-guzzlehttp-psr7",
            "binary_version": "1.4.2-0.1+deb10u2build0.20.04.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55766.json"
Ubuntu:24.04:LTS
php-guzzlehttp-psr7

Package

Name
php-guzzlehttp-psr7
Purl
pkg:deb/ubuntu/php-guzzlehttp-psr7?arch=source&distro=noble

Affected ranges

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

Affected versions

2.*
2.6.0-1
2.6.1-1
2.6.2-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "php-guzzlehttp-psr7",
            "binary_version": "2.6.2-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55766.json"
Ubuntu:25.10
php-guzzlehttp-psr7

Package

Name
php-guzzlehttp-psr7
Purl
pkg:deb/ubuntu/php-guzzlehttp-psr7?arch=source&distro=questing

Affected ranges

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

Affected versions

2.*
2.7.0-3
2.7.1-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "php-guzzlehttp-psr7",
            "binary_version": "2.7.1-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55766.json"
Ubuntu:26.04:LTS
php-guzzlehttp-psr7

Package

Name
php-guzzlehttp-psr7
Purl
pkg:deb/ubuntu/php-guzzlehttp-psr7?arch=source&distro=resolute

Affected ranges

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

Affected versions

2.*
2.7.1-1
2.8.0-1
2.8.0-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "php-guzzlehttp-psr7",
            "binary_version": "2.8.0-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55766.json"
Ubuntu:Pro:22.04:LTS
php-guzzlehttp-psr7

Package

Name
php-guzzlehttp-psr7
Purl
pkg:deb/ubuntu/php-guzzlehttp-psr7?arch=source&distro=esm-apps%2Fjammy

Affected ranges

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

Affected versions

1.*
1.7.0-1
1.8.3-1
1.8.3-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "php-guzzlehttp-psr7",
            "binary_version": "1.8.3-1ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55766.json"