UBUNTU-CVE-2026-27017

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Source
https://ubuntu.com/security/CVE-2026-27017
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27017.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-27017
Upstream
Published
2026-02-23T00:00:00Z
Modified
2026-02-23T23:26:53.480935Z
Severity
  • 2.3 (Low) CVSS_V4 - CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N CVSS Calculator
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

uTLS is a fork of crypto/tls, created to customize ClientHello for fingerprinting resistance while still using it for the handshake. Versions 1.6.0 through 1.8.0 contain a fingerprint mismatch with Chrome when using GREASE ECH, related to cipher suite selection. When Chrome selects the preferred cipher suite in the outer ClientHello and for ECH, it does so consistently based on hardware support—for example, if it prefers AES for the outer cipher suite, it also uses AES for ECH. However, the Chrome parrot in uTLS hardcodes AES preference for outer cipher suites but selects the ECH cipher suite randomly between AES and ChaCha20. This creates a 50% chance of selecting ChaCha20 for ECH while using AES for the outer cipher suite, a combination impossible in Chrome. This issue only affects GREASE ECH; in real ECH, Chrome selects the first valid cipher suite when AES is preferred, which uTLS handles correctly. This issue has been fixed in version 1.8.1.

References

Affected packages

Ubuntu:22.04:LTS / golang-refraction-networking-utls

Package

Name
golang-refraction-networking-utls
Purl
pkg:deb/ubuntu/golang-refraction-networking-utls@0.0~git20201210.2179f28-1?arch=source&distro=jammy

Affected ranges

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

Affected versions

0.*
0.0~git20201210.2179f28-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "golang-refraction-networking-utls-dev",
            "binary_version": "0.0~git20201210.2179f28-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27017.json"

Ubuntu:24.04:LTS / golang-refraction-networking-utls

Package

Name
golang-refraction-networking-utls
Purl
pkg:deb/ubuntu/golang-refraction-networking-utls@1.2.1-2?arch=source&distro=noble

Affected ranges

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

Affected versions

1.*
1.2.1-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "golang-refraction-networking-utls-dev",
            "binary_version": "1.2.1-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27017.json"

Ubuntu:25.10 / golang-refraction-networking-utls

Package

Name
golang-refraction-networking-utls
Purl
pkg:deb/ubuntu/golang-refraction-networking-utls@1.2.1-3.1?arch=source&distro=questing

Affected ranges

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

Affected versions

1.*
1.2.1-3.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "golang-refraction-networking-utls-dev",
            "binary_version": "1.2.1-3.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27017.json"