CVE-2026-25935: Code.vikunja.io/api Cross-Site Scripting Vulnerability

HIGH
Advisory Identifier: GHSA-m4g2-2q66-vc9v
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CWE-80 CWE-79
Published
Advisory Summary

CVE-2026-25935 is a HIGH cross-site scripting vulnerability (CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)) affecting Code.vikunja.io/api libraries in the Go ecosystem. The issue involves vikunja vulnerable to xss via task preview. Remediation is available in the latest vendor maintenance releases.

CVE-2026-25935 at a Glance

CVE Identifier CVE-2026-25935
GHSA Identifier GHSA-m4g2-2q66-vc9v
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
Affected Product Code.vikunja.io/api
Package Ecosystem Go
Published Date
Last Updated

How to Fix CVE-2026-25935

To remediate this vulnerability, upgrade all affected Code.vikunja.io/api dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

code.vikunja.io/api fixed: Latest secure release 
Upgrade code.vikunja.io/api to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for code.vikunja.io/api

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-25935, inspect your project dependencies for Code.vikunja.io/api:

inspect dependencies for code.vikunja.io/api

Analyze the terminal output to locate any version of Code.vikunja.io/api in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS), where the product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages. In Code.vikunja.io/api, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary The task preview component creates a unparented div. The div's `innerHtml` is set to the unescaped description of the task ### Details In the `TaskGlanceTooltip.vue` it temporarily creates a div and sets the `innerHtml` to the description [here](https://github.com/go-vikunja/vikunja/blob/cdca79032526966cb248b72bddcf2a0f888c8a8f/frontend/src/components/tasks/partials/TaskGlanceTooltip.vue#L118). Since there is no escaping on either the server or client side, a malicious user can share a project, create a malicious task, and cause an XSS on hover. ### PoC 1. Create a project 2. Create a task with any description 3. Use the api to update the task with a description containing unescaped HTML (ex: `<img src=x onerror="alert(localStorage.getItem('token'))">` 4. Share the project with any permission level 5. Send malicious project to user and ask them to view task ### Impact Any user on an instance can cause an XSS on another

CVE-2026-25935 Affected Code.vikunja.io/api Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
code.vikunja.io/api
golang/code.vikunja.io/api
Go
≤ 0.24.6

References

GitHub Advisory / Wiki ADVISORY
https://github.com/go-vikunja/vikunja/security/advisories/GHSA-m4g2-2q66-vc9v
NVD — CVE-2026-25935 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-25935
Security Fix Commit FIX COMMIT
https://github.com/go-vikunja/vikunja/commit/dd0b82f00a8c9ded1c19a1e643a197c514be6d37
Code.vikunja.io/api Source Repository REPOSITORY
https://github.com/go-vikunja/vikunja
Code.vikunja.io/api Release RELEASE
https://github.com/go-vikunja/vikunja/releases/tag/v1.1.0
vikunja.io/changelog/vikunja-v... WEB
https://vikunja.io/changelog/vikunja-v1.1.0-was-released

Frequently Asked Questions

What is CVE-2026-25935?
CVE-2026-25935 is a security vulnerability in Code.vikunja.io/api involving Vikunja Vulnerable to XSS Via Task Preview under CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS).
Which Code.vikunja.io/api versions are affected?
Affected versions include releases prior to current release patches across affected packages: code.vikunja.io/api.
What version fixes CVE-2026-25935?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is code.vikunja.io/api affected?
Yes, code.vikunja.io/api is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What CWE is associated with CVE-2026-25935?
CVE-2026-25935 is classified under CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) (The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.).
How can I check Go dependencies for CVE-2026-25935?
Run the dependency tree command: 'inspect dependencies for code.vikunja.io/api'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-m4g2-2q66-vc9v",
  "modified" : "2026-02-11T23:14:19Z",
  "published" : "2026-02-11T18:39:34Z",
  "aliases" : [ "CVE-2026-25935" ],
  "summary" : "Vikunja Vulnerable to XSS Via Task Preview",
  "details" : "### Summary\nThe task preview component creates a unparented div. The div's `innerHtml` is set to the unescaped description of the task\n\n### Details\nIn the `TaskGlanceTooltip.vue` it temporarily creates a div and sets the `innerHtml` to the description [here](https://github.com/go-vikunja/vikunja/blob/cdca79032526966cb248b72bddcf2a0f888c8a8f/frontend/src/components/tasks/partials/TaskGlanceTooltip.vue#L118). Since there is no escaping on either the server or client side, a malicious user can share a project, create a malicious task, and cause an XSS on hover.\n\n### PoC\n1. Create a project\n2. Create a task with any description\n3. Use the api to update the task with a description containing unescaped HTML (ex: `<img src=x onerror=\"alert(localStorage.getItem('token'))\">`\n4. Share the project with any permission level\n5. Send malicious project to user and ask them to view task\n\n### Impact\nAny user on an instance can cause an XSS on another",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "code.vikunja.io/api"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.24.6"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-m4g2-2q66-vc9v"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-25935"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/go-vikunja/vikunja/commit/dd0b82f00a8c9ded1c19a1e643a197c514be6d37"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/go-vikunja/vikunja"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/go-vikunja/vikunja/releases/tag/v1.1.0"
  }, {
    "type" : "WEB",
    "url" : "https://vikunja.io/changelog/vikunja-v1.1.0-was-released"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79", "CWE-80" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-11T18:39:34Z",
    "nvd_published_at" : "2026-02-11T21:16:20Z"
  }
}