USN-8883-2

It was discovered that the Go x/net/idna package incorrectly handled certain Punycode-encoded labels that decoded to ASCII-only labels. An attacker could possibly use this issue to bypass hostname-based access controls and escalate privileges.

References

Affected packages

Ubuntu:22.04:LTS / golang-1.23

Package

Name: golang-1.23
Purl: pkg:deb/ubuntu/golang-1.23?arch=source&distro=jammy

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

1.23.1-1~22.04.3

Affected versions

1.*

1.23.1-1~22.04

1.23.1-1~22.04.2

Ecosystem specific

{
    "availability":  "No subscription required",
    "binaries":  [
        {
            "binary_name":  "golang-1.23",
            "binary_version":  "1.23.1-1~22.04.3"
        },
        {
            "binary_name":  "golang-1.23-go",
            "binary_version":  "1.23.1-1~22.04.3"
        },
        {
            "binary_name":  "golang-1.23-src",
            "binary_version":  "1.23.1-1~22.04.3"
        }
    ]
}

Database specific

cves_map

{
    "cves":  [
        {
            "id":  "CVE-2026-39821",
            "severity":  [
                {
                    "score":  "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N",
                    "type":  "CVSS_V3"
                },
                {
                    "score":  "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N",
                    "type":  "CVSS_V3"
                },
                {
                    "score":  "high",
                    "type":  "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem":  "Ubuntu:22.04:LTS"
}

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8883-2.json"