What is the CVSS score of EUVD-2026-31895?

EUVD-2026-31895 has a CVSS 3.1 base score of 8.7 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N. EPSS exploitation probability: 0.0%.

Which versions of Twenty CRM are affected by EUVD-2026-31895?

Twenty CRM versions 1.18.0 and earlier contain a stored cross-site scripting vulnerability exploitable by any authenticated user through file upload, creating direct paths to session hijacking and…

How to fix or mitigate EUVD-2026-31895?

Within 24 hours: Identify all Twenty CRM deployments and versions in production; establish an inventory of active users and recent file uploads; enable enhanced logging for file upload and session activity. Within 7 days: Disable or restrict HTML/JavaScript file uploads to administrative users only; implement Content Security Policy headers; deploy WAF rules to block XSS payloads; enforce multi-factor authentication for all CRM users. Within 30 days: No vendor-released patch identified at time of analysis-monitor Twenty CRM security advisories weekly and establish a business continuity plan including potential upgrade or migration timeline.

Twenty CRM EUVD-2026-31895

| CVE-2026-44729 HIGH

Cross-site Scripting (XSS) (CWE-79)

2026-05-26 GitHub_M

XSS Twenty

8.7

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

8.7 HIGH

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

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

Analysis Generated

Jun 08, 2026 - 10:15 vuln.today

DescriptionGitHub Advisory

Twenty is an open source CRM. In 1.18.0 and earlier, the file serving endpoints in Twenty CRM at /files/* and /file/:fileFolder/:id serve uploaded files using fileStream.pipe(res) without setting any Content-Type, Content-Disposition, or X-Content-Type-Options response headers. This allows an authenticated attacker to upload an HTML file containing JavaScript, which will be rendered by the victim's browser in the context of the Twenty CRM domain when accessed - enabling session hijacking, account takeover, and data theft.

AnalysisAI

Stored cross-site scripting in Twenty CRM versions 1.18.0 and earlier allows authenticated users to upload HTML/JavaScript files that the application then serves without security headers, enabling execution in the CRM's origin. Successful exploitation leads to session hijacking, account takeover, and theft of CRM data. No public exploit identified at time of analysis, and EPSS exploitation probability is 0.03% (10th percentile), though SSVC rates technical impact as total.

Technical ContextAI

Twenty is an open-source CRM platform (cpe:2.3:a:twentyhq:twenty). The vulnerability resides in the file-serving endpoints /files/* and /file/:fileFolder/:id, which stream uploaded files back to clients via fileStream.pipe(res) without setting Content-Type, Content-Disposition: attachment, or X-Content-Type-Options: nosniff. Without nosniff, modern browsers MIME-sniff response bodies and will render an uploaded .html file as a document; without Content-Disposition: attachment, the browser inlines rather than downloads it. This is a classic CWE-79 (stored XSS) realized through a content-type confusion / unsafe file-serving pattern, with the attacker-controlled JavaScript executing in the Twenty CRM origin and inheriting access to session cookies, CSRF tokens, and authenticated API endpoints.

RemediationAI

No vendor-released patch version is identified in the supplied data; consult GHSA-f5h2-3qw5-3qp7 (https://github.com/twentyhq/twenty/security/advisories/GHSA-f5h2-3qw5-3qp7) and upgrade to the fixed Twenty release referenced there once confirmed. As compensating controls until upgrade, place the /files/* and /file/:fileFolder/:id endpoints behind a reverse proxy (nginx, Caddy, Cloudflare) that injects Content-Type: application/octet-stream or the original safe MIME type, Content-Disposition: attachment, and X-Content-Type-Options: nosniff on responses - this forces download instead of inline rendering at the cost of breaking legitimate inline image/PDF previews. Optionally restrict upload MIME types to a non-HTML allowlist and serve user uploads from a separate sandbox domain so any executed script cannot reach the CRM session origin; the trade-off is added deployment complexity and CORS configuration. Tighten file-upload permissions to trusted users only to shrink the attacker population, accepting that this does not eliminate the bug for malicious insiders.