CVE-2026-35601 Vikunja has an iCalendar Property Injection via CRLF in CalDAV Task Output
Attackers can inject arbitrary iCalendar properties into CalDAV task outputs via CRLF injection in task titles, potentially altering client behavior.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-35601?
CVE-2026-35601 is a medium-severity vulnerability in go-vikunja vikunja, published on 10 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the CalDAV output generator builds iCalendar VTODO entries via raw string concatenation without applying RFC 5545 TEXT value escaping. User-controlled task titles containing CRLF characters break the iCalendar property boundary, allowing injection of arbitrary iCalendar properties such as ATTACH, VALARM, or ORGANIZER. This vulnerability is fixed in 2.3.0.
Weakness: CWE-93
Which versions are affected by CVE-2026-35601?
3 open source packages ship an affected version, including code.vikunja.io/api. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
code.vikunja.io/api Go | All versions | None |
code.vikunja.io/api Go | All versions | 2.3.0 |
code.vikunja.io/api Go | All versions | 2.3.0 |
Products include Vikunja Vikunja.
How do I fix CVE-2026-35601?
Upgrade code.vikunja.io/api to 2.3.0 or later.
Is CVE-2026-35601 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35601 exists.
Other vulnerabilities in go-vikunja vikunja
- CVE-2026-28268 Vikunja Vulnerable to Account Takeover via Password Reset Token Reuse
- CVE-2026-27575 Vijkunja has Weak Password Policy Combined with Persistent Sessions After Password Change
- CVE-2026-25935 Vikunja Affected by XSS Via Task Preview
- CVE-2026-35595 Vikunja Affected by Privilege Escalation via Project Reparenting
- CVE-2026-33316 Vikunja’s Improper Access Control Enables Bypass of Administrator-Imposed Account Disablement
Sources
Also known as GHSA-2g7h-7rqr-9p4r, GO-2026-4951.