UBUNTU-CVE-2026-9537

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Source
https://ubuntu.com/security/CVE-2026-9537
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-9537.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-9537
Upstream
Published
2026-07-17T16:17:00Z
Modified
2026-07-29T10:19:00Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Mojo::JWT versions before 1.02 for Perl verify HMAC signatures with a non-constant-time string comparison. The decode() method compares the supplied signature to the recomputed HMAC with Perl's eq operator, which stops at the first differing byte, so the comparison time varies with the number of matching leading bytes. A caller that decodes attacker supplied tokens leaks the expected signature through this timing variation, which can be aggregated over many requests to recover the signature and forge a token.

References

Affected packages

Ubuntu:18.04:LTS / libmojo-jwt-perl

Package

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

Affected ranges

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

Affected versions

0.*
0.05-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libmojo-jwt-perl",
            "binary_version": "0.05-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-9537.json"

Ubuntu:20.04:LTS / libmojo-jwt-perl

Package

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

Affected ranges

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

Affected versions

0.*
0.08-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libmojo-jwt-perl",
            "binary_version": "0.08-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-9537.json"

Ubuntu:22.04:LTS / libmojo-jwt-perl

Package

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

Affected ranges

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

Affected versions

0.*
0.09-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libmojo-jwt-perl",
            "binary_version": "0.09-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-9537.json"

Ubuntu:24.04:LTS / libmojo-jwt-perl

Package

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

Affected ranges

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

Affected versions

0.*
0.09-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libmojo-jwt-perl",
            "binary_version": "0.09-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-9537.json"

Ubuntu:26.04:LTS / libmojo-jwt-perl

Package

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

Affected ranges

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

Affected versions

1.*
1.01-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "libmojo-jwt-perl",
            "binary_version": "1.01-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-9537.json"