CVE-2026-39311

Trilium Notes is a cross-platform, hierarchical note taking application focused on building large personal knowledge bases. Versions 0.102.1 and prior contain a critical security flaw where lack of SVG sanitization combined with a disabled Content Security Policy (CSP) and a publicly reachable backend execution API results in an unauthenticated Remote Code Execution (RCE). The vulnerability arises from an insecure-by-design architecture: Trilium serves SVG attachments with the image/svg+xml MIME type without any sanitization, and it explicitly disables Helmet's Content Security Policy middleware, removing the primary defense against script execution in served assets. Because the malicious SVG runs under the Same-Origin Policy, it can issue a fetch('/') to extract the csrfToken from the document body. With that token, it can send a signed request to /api/script/exec to execute arbitrary Node.js code on the server. An attacker can compromise the entire server instance simply by tricking an authenticated user into viewing a shared SVG attachment. The issue has been fixed in version 0.102.2.

CVSS v3 6.8 MEDIUM

6.8^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.0 / Impact : 5.3

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required HIGH

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://github.com/TriliumNext/Trilium/releases/tag/v0.102.2
https://github.com/TriliumNext/Trilium/security/advisories/GHSA-p837-cxw3-m964
https://github.com/TriliumNext/Trilium/security/advisories/GHSA-p837-cxw3-m964

Configurations

No configuration.

History

20 May 2026, 20:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-05-20 20:16

Updated : 2026-06-17 10:41

NVD link : CVE-2026-39311

Mitre link : CVE-2026-39311

CVE.ORG link : CVE-2026-39311

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CWE-94

Improper Control of Generation of Code ('Code Injection')

{"id": "CVE-2026-39311", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-39311", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-05-20T19:26:55.817058Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 6.8, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:L/A:H", "integrityImpact": "LOW", "userInteraction": "REQUIRED", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "HIGH", "confidentialityImpact": "LOW"}, "impactScore": 5.3, "exploitabilityScore": 1.0}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "TriliumNext", "product": "Trilium", "versions": [{"status": "affected", "version": "< 0.102.2"}]}]}], "published": "2026-05-20T20:16:39.363", "references": [{"url": "https://github.com/TriliumNext/Trilium/releases/tag/v0.102.2", "source": "security-advisories@github.com"}, {"url": "https://github.com/TriliumNext/Trilium/security/advisories/GHSA-p837-cxw3-m964", "source": "security-advisories@github.com"}, {"url": "https://github.com/TriliumNext/Trilium/security/advisories/GHSA-p837-cxw3-m964", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-79"}, {"lang": "en", "value": "CWE-94"}]}], "descriptions": [{"lang": "en", "value": "Trilium Notes is a cross-platform, hierarchical note taking application focused on building large personal knowledge bases. Versions 0.102.1 and prior contain a critical security flaw where lack of SVG sanitization combined with a disabled Content Security Policy (CSP) and a publicly reachable backend execution API results in an unauthenticated Remote Code Execution (RCE). The vulnerability arises from an insecure-by-design architecture: Trilium serves SVG attachments with the image/svg+xml MIME type without any sanitization, and it explicitly disables Helmet's Content Security Policy middleware, removing the primary defense against script execution in served assets. Because the malicious SVG runs under the Same-Origin Policy, it can issue a fetch('/') to extract the csrfToken from the document body. With that token, it can send a signed request to /api/script/exec to execute arbitrary Node.js code on the server. An attacker can compromise the entire server instance simply by tricking an authenticated user into viewing a shared SVG attachment. The issue has been fixed in version 0.102.2."}], "lastModified": "2026-06-17T10:41:54.030", "sourceIdentifier": "security-advisories@github.com"}