Detections
Analytics

SCA: security update for icalendar (GHSA-pv9c-9mfh-hvxq)

medium Tenable Self-Hosted Container Security Plugin ID 439177

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - iCalendar is a Ruby library for dealing with iCalendar files in the iCalendar format defined by RFC-5545.
 Starting in version 2.0.0 and prior to version 2.12.2, .ics serialization does not properly sanitize URI
 property values, enabling ICS injection through attacker-controlled input, adding arbitrary calendar lines
 to the output. `Icalendar::Values::Uri` falls back to the raw input string when `URI.parse` fails and
 later serializes it with `value.to_s` without removing or escaping `\r` or `\n` characters. That value is
 embedded directly into the final ICS line by the normal serializer, so a payload containing CRLF can
 terminate the original property and create a new ICS property or component. (It looks like you can inject
 via url, source, image, organizer, attach, attendee, conference, tzurl because of this). Applications that
 generate `.ics` files from partially untrusted metadata are impacted. As a result, downstream calendar
 clients or importers may process attacker-supplied content as if it were legitimate event data, such as
 added attendees, modified URLs, alarms, or other calendar fields. Version 2.12.2 contains a patch for the
 issue. (CVE-2026-33635)

Solution

Update the icalendar library and its related packages to version 2.12.2 or later.

See Also

https://github.com/advisories/GHSA-pv9c-9mfh-hvxq

Plugin Details

Severity: Medium

ID: 439177

Version: Revision 1.6

Type: Local

Family: SCA Checks

Published: 3/25/2026

Updated: 7/2/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 1.2

Percentile: 0.01

Vendor

Vendor Severity: Medium

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.9

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N

CVSS Score Source: CVE-2026-33635

CVSS v3

Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 3/24/2026

Vulnerability Publication Date: 3/24/2026

Reference Information

CVE: CVE-2026-33635

cwe: CWE-93