CVE-2026-50873

CRITICAL

flatnotes 5.5.4 - Arbitrary File Upload and Remote Code Execution via Attachment Handling

Title source: llm
STIX 2.1

Description

An arbitrary file upload vulnerability in the attachment handling component of flatnotes v5.5.4 allows attackers to execute arbitrary code via uploading a crafted HTML or SVG file.

References (1)

Core 1

Scores

CVSS v3 9.8
EPSS 0.0044
EPSS Percentile 35.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact total

Details

CWE
CWE-434
Status published
Published Jun 15, 2026
Tracked Since Jun 16, 2026