SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-63765

Chatwoot before 4.16.0 contains an authentication bypass vulnerability in the direct uploads controller that allows unauthenticated attackers to create arbitrary ActiveStorage blobs in any tenant account.

HIGH 8.8EPSS 0.70%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.70%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Chatwoot before 4.16.0 contains an authentication bypass vulnerability in the direct uploads controller that allows unauthenticated attackers to create arbitrary ActiveStorage blobs in any tenant account. Attackers can exploit missing authentication checks to resolve any account and conversation, then obtain signed PUT URLs to write arbitrary data to the application's storage backend.

CVSS 4.0
8.8 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.70% probability · 51th percentile
CISA KEV
Not listed
Weakness
CWE-306
Source
disclosure@vulncheck.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.