VulnerabilityPublished 25 Feb 2026

CVE-2026-27616: vikunja · Cross-site Scripting

Affects vikunjaSource CVE Database V5

Compare

Not known to be exploited · CVSS 7.3 High : upgrade to 2.0.0 soon.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

7.3High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.0.0

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade vikunja and github.com/go-vikunja/vikunja to 2.0.0.

Affected software

Product	Affected	Fixed in
go-vikunjavikunja	Affected <2.0.0	Fixed in 2.0.0
Gogithub.com/go-vikunja/vikunja`pkg:golang/github.com/go-vikunja/vikunja`Other threats	Affected <2.0.0	Fixed in 2.0.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Organizations should immediately upgrade Vikunja to version 2.0.0 or later, where the vulnerability is patched. Until upgrading is possible, administrators should disable or restrict SVG file uploads to prevent malicious content introduction. Implementing server-side validation and sanitization of SVG files before storage is critical to neutralize embedded scripts. Additionally, consider removing or restricting the use of localStorage for storing authentication tokens, moving to more secure storage mechanisms such as HttpOnly cookies to prevent JavaScript access. Educate users to avoid clicking on suspicious links or accessing untrusted SVG attachments. Employ Content Security Policy (CSP) headers to restrict script execution and reduce the impact of potential XSS attacks. Regularly audit task attachments for malicious content and monitor logs for unusual access patterns. Finally, maintain an incident response plan to quickly address any exploitation attempts.

Description

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 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.

Impact

This vulnerability can have severe consequences for organizations using Vikunja versions prior to 2.0.0. Exploitation allows attackers to execute arbitrary JavaScript in the context of authenticated users, leading to theft of authentication tokens stored in localStorage. This can result in unauthorized account access, data theft, and potential lateral movement within an organization’s task management environment. Confidentiality and integrity of user data are at high risk, potentially exposing sensitive project information or internal communications. Although availability is not directly impacted, the breach of user sessions can lead to significant operational disruptions and loss of trust. Organizations relying on Vikunja for task management, especially those with sensitive or regulated data, face increased risk of targeted attacks leveraging this vulnerability. The requirement for user interaction (accessing the malicious SVG URL) means phishing or social engineering could be used to trigger exploitation. The lack of known exploits in the wild suggests limited immediate threat but the ease of exploitation and high impact warrant urgent remediation.

CWE-79Improper Neutralization of Input During Web Page Generation (Cross-site Scripting) (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation · Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide…
OWASP Cheat Sheets
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.3 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
DOM-Based XSS (opens in a new tab)
Reflected XSS (opens in a new tab)
Stored XSS (opens in a new tab)
Cross-Site Scripting (XSS) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 5 Mar 2026, 09:58 UTC

WeaknessesCWE-79

Technical details

References

Community reviews

Related threats