UBUNTU-CVE-2026-77399

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Source
https://ubuntu.com/security/CVE-2026-77399
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77399.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-77399
Upstream
Published
2026-09-22T19:16:00Z
Modified
2026-09-24T02:00:47Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

icalendar is an RFC 5545 compatible parser and generator of iCalendar files for Python. From 6.1.0 until 7.2.2, vInt.from_ical accepts an attacker-controlled VALARM REPEAT value and applications that request alarm times can eagerly expand it without an application-level limit. Alarms.times and Alarms.active reach the unbounded expansion in versions starting with 6.1.0, while Alarm.triggers adds a second affected path starting with 7.0.0. Parsing alone does not trigger the issue, but accessing these properties can consume excessive CPU time and heap memory and terminate or stall a service. This issue is fixed in version 7.2.2.

References

Affected packages

Ubuntu:16.04:LTS
python-icalendar

Package

Name
python-icalendar
Purl
pkg:deb/ubuntu/python-icalendar?arch=source&distro=xenial

Affected ranges

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

Affected versions

3.*
3.8-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python-icalendar",
            "binary_version":  "3.8-1"
        },
        {
            "binary_name":  "python3-icalendar",
            "binary_version":  "3.8-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77399.json"
Ubuntu:18.04:LTS
python-icalendar

Package

Name
python-icalendar
Purl
pkg:deb/ubuntu/python-icalendar?arch=source&distro=bionic

Affected ranges

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

Affected versions

3.*
3.8-2
3.11.7-3
4.*
4.0.0-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python-icalendar",
            "binary_version":  "4.0.0-1"
        },
        {
            "binary_name":  "python3-icalendar",
            "binary_version":  "4.0.0-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77399.json"
Ubuntu:20.04:LTS
python-icalendar

Package

Name
python-icalendar
Purl
pkg:deb/ubuntu/python-icalendar?arch=source&distro=focal

Affected ranges

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

Affected versions

4.*
4.0.3-3
4.0.3-4

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python3-icalendar",
            "binary_version":  "4.0.3-4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77399.json"
Ubuntu:22.04:LTS
python-icalendar

Package

Name
python-icalendar
Purl
pkg:deb/ubuntu/python-icalendar?arch=source&distro=jammy

Affected ranges

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

Affected versions

4.*
4.0.3-4

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python3-icalendar",
            "binary_version":  "4.0.3-4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77399.json"
Ubuntu:24.04:LTS
python-icalendar

Package

Name
python-icalendar
Purl
pkg:deb/ubuntu/python-icalendar?arch=source&distro=noble

Affected ranges

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

Affected versions

5.*
5.0.7-1
5.0.11-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python3-icalendar",
            "binary_version":  "5.0.11-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77399.json"
Ubuntu:26.04:LTS
python-icalendar

Package

Name
python-icalendar
Purl
pkg:deb/ubuntu/python-icalendar?arch=source&distro=resolute

Affected ranges

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

Affected versions

6.*
6.0.1-3
6.3.1-1
6.3.1-2

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python3-icalendar",
            "binary_version":  "6.3.1-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-77399.json"