GHSA-g82g-m9vx-vhjg is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in kimai/kimai. O3 Security confirms whether GHSA-g82g-m9vx-vhjg is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Kimai has Stored XSS via Incomplete HTML Attribute Escaping in Team Member Widget
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
kimai/kimaiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The client-side escapeForHtml() function in KimaiEscape.js, introduced in commit 89bfa82c (#2959) to fix a JavaScript XSS vulnerability, only escapes <, >, and & but does not escape " (double quote) or ' (single quote). When user-controlled data (profile alias) is placed in an HTML attribute context (title="__DISPLAY__") via the team member form prototype and rendered through innerHTML, the missing quote escaping allows HTML attribute injection, resulting in Stored XSS.
Details
Incomplete security patch. The escapeForHtml() function was meant to prevent XSS but missed quote characters, which are critical for HTML attribute context escaping.
Vulnerable code — assets/js/plugins/KimaiEscape.js:29-33:
const tagsToReplace = {
'&': '&',
'<': '<',
'>': '>',
// MISSING: '"': '"'
// MISSING: "'": '''
};
Affected code files:
assets/js/plugins/KimaiEscape.js:24-38— incomplete escape functionassets/js/forms/KimaiTeamForm.js:77,86— replacement + innerHTMLtemplates/macros/widgets.html.twig:126—title="{{ tooltip }}"in avatar macrotemplates/form/blocks.html.twig:104—{{ widgets.avatar('__INITIALS__', '__COLOR__', '__DISPLAY__') }}
PoC
Please extract the uploaded compressed file before proceeding
- ./setup.sh
- ./poc_xss.sh
Impact
- Stored XSS: payload persists in the database (user alias field)
- Privilege escalation: ROLE_USER injects XSS that executes in ROLE_ADMIN/ROLE_SUPER_ADMIN browser session
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | kimai/kimai | all versions | 2.53.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for kimai/kimai. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update kimai/kimai to 2.53.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-g82g-m9vx-vhjg is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-g82g-m9vx-vhjg is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-g82g-m9vx-vhjg. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-g82g-m9vx-vhjg in your dependencies?
O3 detects GHSA-g82g-m9vx-vhjg across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.