UBUNTU-CVE-2026-19953

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Source
https://ubuntu.com/security/CVE-2026-19953
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19953.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-19953
Upstream
Published
2026-08-31T18:17:00Z
Modified
2026-09-03T16:04:21Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

URI versions before 5.36 for Perl encode non-NFC host names to non-standard punycode labels via missing normalization in nameprep. nameprep lowercases each host label but performs no Unicode normalization. IDNA requires a label to be normalized to Form C before it is encoded (RFC 5891), so a label that is not already in NFC is encoded to a different A-label than its normalized form. A label built from the precomposed Devanagari sequence U+0958 U+093E encodes to xn--72b5c without normalization but to xn--11b2fg after NFC normalization, and xn--72b5c does not round-trip back to the original label. Any caller that reads host() from a URI built from untrusted input and uses it for a security decision (an allow or deny list, an SSRF filter, deduplication, a cache key) sees the non-standard label, while a client that fetches the same URL resolves the NFC form, so the check and the fetch can disagree about the host.

References

Affected packages

Ubuntu:14.04:LTS
liburi-perl

Package

Name
liburi-perl
Purl
pkg:deb/ubuntu/liburi-perl?arch=source&distro=trusty

Affected ranges

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

Affected versions

1.*
1.60-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "liburi-perl",
            "binary_version":  "1.60-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19953.json"
Ubuntu:16.04:LTS
liburi-perl

Package

Name
liburi-perl
Purl
pkg:deb/ubuntu/liburi-perl?arch=source&distro=xenial

Affected ranges

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

Affected versions

1.*
1.69-1
1.71-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "liburi-perl",
            "binary_version":  "1.71-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19953.json"
Ubuntu:18.04:LTS
liburi-perl

Package

Name
liburi-perl
Purl
pkg:deb/ubuntu/liburi-perl?arch=source&distro=bionic

Affected ranges

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

Affected versions

1.*
1.72-1
1.72-2
1.73-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "liburi-perl",
            "binary_version":  "1.73-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19953.json"
Ubuntu:20.04:LTS
liburi-perl

Package

Name
liburi-perl
Purl
pkg:deb/ubuntu/liburi-perl?arch=source&distro=focal

Affected ranges

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

Affected versions

1.*
1.76-1
1.76-2

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "liburi-perl",
            "binary_version":  "1.76-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19953.json"
Ubuntu:22.04:LTS
liburi-perl

Package

Name
liburi-perl
Purl
pkg:deb/ubuntu/liburi-perl?arch=source&distro=jammy

Affected ranges

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

Affected versions

5.*
5.08-1
5.10-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "liburi-perl",
            "binary_version":  "5.10-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19953.json"
Ubuntu:24.04:LTS
liburi-perl

Package

Name
liburi-perl
Purl
pkg:deb/ubuntu/liburi-perl?arch=source&distro=noble

Affected ranges

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

Affected versions

5.*
5.19-2
5.21-1
5.25-1
5.27-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "liburi-perl",
            "binary_version":  "5.27-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19953.json"
Ubuntu:26.04:LTS
liburi-perl

Package

Name
liburi-perl
Purl
pkg:deb/ubuntu/liburi-perl?arch=source&distro=resolute

Affected ranges

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

Affected versions

5.*
5.30-1
5.34-2build1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "liburi-perl",
            "binary_version":  "5.34-2build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19953.json"