SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-63100

Maybe through 0.6.0 contains a missing authorization vulnerability that allows authenticated low-privilege member-role users to access and modify global hosting settings by exploiting unprotected show and update actions in the…

HIGH 7.1EPSS 0.35%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.35%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Maybe through 0.6.0 contains a missing authorization vulnerability that allows authenticated low-privilege member-role users to access and modify global hosting settings by exploiting unprotected show and update actions in the Settings::HostingsController, where the before_action ensure_admin filter is applied only to the clear_cache action. Attackers can read the operator's Synth API key rendered in plaintext via a form field value attribute, overwrite it with an attacker-controlled value, toggle public registration settings, and disable email confirmation requirements to disrupt the entire instance.

CVSS 4.0
7.1 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/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
0.35% probability · 29th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-862
Source
disclosure@vulncheck.com
EPSS trend
0%3%5%26 October 2026: 0.35%26 October 202626 October 2026

EPSS 0.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.