Vikunja has an iCalendar Property Injection via CRLF in CalDAV Task Output
Priority MEDIUM 52CWE-93Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00203 10th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed vikunja (go-vikunja): 2.3.0code.vikunja.io/api (Go): 2.3.0
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| go-vikunja | vikunja | before 2.3.0 | 2.3.0 | Patch available | CNA |
| — | code.vikunja.io/api (Go) | before 2.3.0 | 2.3.0 | Patch available | GHSA-2g7h-7rqr-9p4r |
- vikunja Vendorgo-vikunja Affected before 2.3.0 Fixed in 2.3.0 Patch available CNA
- code.vikunja.io/api (Go) Vendor— Affected before 2.3.0 Fixed in 2.3.0 Patch available GHSA-2g7h-7rqr-9p4r
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:* | before 2.3.0 | Vulnerable | go-vikunja |
- cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:* Versions before 2.3.0 Vulnerable ·go-vikunja
Remediation
- Fix · CNA vikunja (go-vikunja) Fixed in 2.3.0
- Fix · GHSA-2g7h-7rqr-9p4r code.vikunja.io/api (Go) Fixed in 2.3.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-35601
- 2026-10-03 Alias added: GHSA-2g7h-7rqr-9p4r
References
More go-vikunja Vikunja vulnerabilities
- TI-2026-21967 Vijkunja has Weak Password Policy Combined with Persistent Sessions After Password Change CVSS 3.1CRITICAL 9.1
- TI-2026-26971 Vikunja ahs a TOTP Two-Factor Authentication Bypass via OIDC Login Path CVSS 3.1CRITICAL 9.1
- TI-2026-26060 Vikunja Vulnerable to Link Share Hash Disclosure via ReadAll Endpoint Enables Permission Escalation CVSS 3.1HIGH 7.5
- TI-2026-20965 Vikunja Affected by XSS Via Task Preview CVSS 4.0HIGH 8.6
- TI-2026-27698 Vikunja Affected by Privilege Escalation via Project Reparenting CVSS 3.1HIGH 8.3
- TI-2026-25727 Vikunja’s Improper Access Control Enables Bypass of Administrator-Imposed Account Disablement CVSS 3.1HIGH 8.1
Sources
- CVE-2026-35601 · CVE Program
- CVE-2026-35601 · NVD
- FIRST EPSS
- GHSA-2g7h-7rqr-9p4r · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences