UBUNTU-CVE-2026-126135

Source
https://ubuntu.com/security/CVE-2026-126135
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126135.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-126135
Upstream
  • CVE-2026-126135
Published
2026-11-12T00:00:00Z
Modified
2026-11-12T23:46:39Z
Severity
  • Ubuntu - medium
Summary
[none]
Details

If an attacker was able to perform a man-in-the-middle attack on an SMTP or POP3 server connection using STARTTLS, the attacker could inject server responses before the TLS handshake completed. Thunderbird would process these responses after the handshake, as if they had been received from the server over the encrypted connection. This could be used to make Thunderbird report a different outcome for sending or fetching mail, and to show attacker-controlled text in error messages. The encrypted connection itself was not compromised, and credentials were not exposed. Connections using SSL/TLS instead of STARTTLS were not affected. This vulnerability was fixed in Thunderbird 160 and Thunderbird 153.7.

References

Affected packages

Ubuntu:22.04:LTS / thunderbird

Package

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

Affected ranges

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

Affected versions

1:91.*
1:91.1.2+build1-0ubuntu1
1:91.3.0+build2-0ubuntu1
1:91.3.1+build1-0ubuntu1
1:91.3.2+build1-0ubuntu1
1:91.4.0+build1.1-0ubuntu1
1:91.4.0+build2-0ubuntu1
1:91.5.0+build1-0ubuntu1
1:91.5.1+build1-0ubuntu1
1:91.6.1+build1-0ubuntu1
1:91.7.0+build1-0ubuntu1
1:91.7.0+build2-0ubuntu1
1:91.8.0+build2-0ubuntu1
1:91.9.1+build1-0ubuntu0.22.04.1
1:91.11.0+build2-0ubuntu0.22.04.1
1:102.*
1:102.2.2+build1-0ubuntu0.22.04.1
1:102.4.2+build2-0ubuntu0.22.04.1
1:102.7.1+build2-0ubuntu0.22.04.1
1:102.8.0+build2-0ubuntu0.22.04.1
1:102.9.0+build1-0ubuntu0.22.04.1
1:102.10.0+build2-0ubuntu0.22.04.1
1:102.11.0+build1-0ubuntu0.22.04.1
1:102.13.0+build1-0ubuntu0.22.04.1
1:102.15.0+build1-0ubuntu0.22.04.1
1:102.15.1+build1-0ubuntu0.22.04.1
1:115.*
1:115.3.1+build1-0ubuntu0.22.04.2
1:115.4.1+build1-0ubuntu0.22.04.1
1:115.5.0+build1-0ubuntu0.22.04.1
1:115.6.0+build2-0ubuntu0.22.04.1
1:115.8.1+build1-0ubuntu0.22.04.1
1:115.9.0+build1-0ubuntu0.22.04.1
1:115.10.1+build1-0ubuntu0.22.04.1
1:115.11.0+build2-0ubuntu0.22.04.1
1:115.12.0+build3-0ubuntu0.22.04.1
1:115.13.0+build5-0ubuntu0.22.04.1
1:115.15.0+build1-0ubuntu0.22.04.1
1:115.16.0+build2-0ubuntu0.22.04.1
1:115.18.0+build1-0ubuntu0.22.04.1
1:128.*
1:128.12.0+build1-0ubuntu0.22.04.1
1:140.*
1:140.7.1+build1-0ubuntu0.22.04.1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "thunderbird",
            "binary_version": "1:140.7.1+build1-0ubuntu0.22.04.1"
        },
        {
            "binary_name": "thunderbird-gnome-support",
            "binary_version": "1:140.7.1+build1-0ubuntu0.22.04.1"
        },
        {
            "binary_name": "thunderbird-mozsymbols",
            "binary_version": "1:140.7.1+build1-0ubuntu0.22.04.1"
        },
        {
            "binary_name": "xul-ext-calendar-timezones",
            "binary_version": "1:140.7.1+build1-0ubuntu0.22.04.1"
        },
        {
            "binary_name": "xul-ext-gdata-provider",
            "binary_version": "1:140.7.1+build1-0ubuntu0.22.04.1"
        },
        {
            "binary_name": "xul-ext-lightning",
            "binary_version": "1:140.7.1+build1-0ubuntu0.22.04.1"
        }
    ]
}

Database specific

source
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126135.json"

Ubuntu:24.04:LTS / thunderbird

Package

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

Affected ranges

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

Affected versions

1:115.*
1:115.3.1+build1-0ubuntu1
1:115.4.1+build1-0ubuntu1
1:115.4.3+build1-0ubuntu1
1:115.5.0+build1-0ubuntu1
1:115.5.1+build1-0ubuntu1
1:115.5.2+build2-0ubuntu1
1:115.6.0+build1-0ubuntu1
1:115.6.0+build2-0ubuntu1
1:115.6.1+build1-0ubuntu1
1:115.8.0+build1-0ubuntu1
1:115.8.1+build1+snap2
1:115.8.1+build1+snap3
Other
2:1snap1-0ubuntu1
2:1snap1-0ubuntu3

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "thunderbird",
            "binary_version": "2:1snap1-0ubuntu3"
        }
    ]
}

Database specific

source
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126135.json"

Ubuntu:26.10 / thunderbird

Package

Name
thunderbird
Purl
pkg:deb/ubuntu/thunderbird?arch=source&distro=stonking

Affected ranges

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

Affected versions

Other
2:1snap1-0ubuntu5

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "thunderbird",
            "binary_version": "2:1snap1-0ubuntu5"
        }
    ]
}

Database specific

source
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126135.json"

Ubuntu:26.04:LTS / thunderbird

Package

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

Affected ranges

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

Affected versions

Other
2:1snap1-0ubuntu3
2:1snap1-0ubuntu4
2:1snap1-0ubuntu5

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "thunderbird",
            "binary_version": "2:1snap1-0ubuntu5"
        }
    ]
}

Database specific

source
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-126135.json"