Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:NSummary
CVE-2026-27616 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Vikunja Vikunja. Its CVSS base score is 7.3 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 37th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-27616 is a stored cross-site scripting (XSS) vulnerability, classified under CWE-79, affecting Vikunja, an open-source self-hosted task management platform. Prior to version 2.0.0, Vikunja permits users to upload SVG files as task attachments without sanitizing their content. SVG, an XML-based format, supports JavaScript execution through elements like <script> tags or event handlers such as onload. When an uploaded SVG is accessed via its direct URL, it renders inline in the browser under the application's origin, allowing embedded JavaScript to execute in the context of the authenticated user. The vulnerability was published on 2026-02-25 and carries a CVSS v3.1 base score of 7.3 (AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N).
An attacker with low privileges (PR:L), such as any authenticated user, can exploit this by uploading a malicious SVG file containing JavaScript payloads as a task attachment. Exploitation requires a victim user (also authenticated) to interact by accessing the SVG's direct URL (UI:R), at which point the JavaScript executes in the victim's browser session. This grants access to the victim's authentication token stored in localStorage, enabling the attacker to exfiltrate it and potentially impersonate the victim for further actions, resulting in high confidentiality and integrity impacts.
The official GitHub security advisory (GHSA-7jp5-298q-jg98) documents the issue, including a proof-of-concept in an attached PDF. Vikunja's changelog confirms that version 2.0.0 patches the vulnerability by addressing SVG content sanitization during uploads. Security practitioners should advise upgrading to version 2.0.0 or later to mitigate the risk.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8752
Vulnerability Data
Vikunja is an open-source self-hosted task management platform. Prior to version 2.0.0, the application allows users to upload SVG files as task attachments. SVG is an XML-based format that supports JavaScript execution through elements such as <script> tags or event…
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handlers like onload. The application does not sanitize SVG content before storing it. When the uploaded SVG file is accessed via its direct URL, it is rendered inline in the browser under the application's origin. As a result, embedded JavaScript executes in the context of the authenticated user. Because the authentication token is stored in localStorage, it is accessible via JavaScript and can be retrieved by a malicious payload. Version 2.0.0 patches this issue.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.1.2V1.3.2
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover missing or incorrect input neutralization through targeted web-application tests.
Input validation directly enforces neutralization of untrusted data before it reaches web output generation.
Output filtering can catch or sanitize unneutralized script content before it is served to users.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).
Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.
Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.
Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.
Requiring language-specific secure-coding standards and automated scanning during the SDLC catches missing output encoding or improper neutralization of untrusted data before the software reaches production.
Secure-coding standards, SAST scans and removal of insecure code samples together eliminate the failure to neutralize script content that produces cross-site scripting flaws.
Webpage malware scanning and block-listing of known malicious sites reduce the likelihood that reflected or stored script payloads reach a user’s browser.