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Package details: pkg:gem/icalendar@2.8.0
purl pkg:gem/icalendar@2.8.0
Next non-vulnerable version 2.12.2
Latest non-vulnerable version 2.12.2
Risk 3.1
Vulnerabilities affecting this package (1)
Vulnerability Summary Fixed by
VCID-ge52-te2z-17gn
Aliases:
CVE-2026-33635
GHSA-pv9c-9mfh-hvxq
iCalendar has ICS injection via unsanitized URI property values ### Summary .ics serialization does not properly sanitize URI property values, enabling ICS injection through attacker-controlled input, adding arbitrary calendar lines to the output. ### Details `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) Relevant code: - `lib/icalendar/values/uri.rb:16` ### Impact 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. ## Fix Reject raw CR and LF characters in `URI`-typed values before serialization, or escape/encode them so they cannot terminate the current ICS content line.
2.12.2
Affected by 0 other vulnerabilities.
Vulnerabilities fixed by this package (0)
Vulnerability Summary Aliases
This package is not known to fix vulnerabilities.

Date Actor Action Vulnerability Source VulnerableCode Version
2026-06-06T07:33:48.792537+00:00 GitLab Importer Affected by VCID-ge52-te2z-17gn https://gitlab.com/gitlab-org/advisories-community/-/blob/main/gem/icalendar/CVE-2026-33635.yml 38.6.0