CVE-2026-33635 details an ICS injection vulnerability in the iCalendar Ruby library, affecting versions 2.0.0 through 2.12.1, where improper sanitization of URI property values allows attackers to inject arbitrary calendar lines into generated .ics files. Rated with a CVSS score of 4.3 (Medium), this flaw requires user interaction but can be exploited over the network with low complexity. Successful exploitation could lead to downstream calendar clients processing attacker-supplied content, such as added attendees or modified URLs, as legitimate event data. Currently, there is no evidence of active exploitation, public exploit code, or significant community discussion regarding this vulnerability.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 2.0.0, < 2.12.2CPE matchmatch criteria | cpe:2.3:a:icalendar_project:icalendar:*:*:*:*:*:ruby:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
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