SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2025-63416

** exclusively-hosted-service ** A Stored Cross-Site Scripting (XSS) vulnerability in the chat functionality of the SelfBest platform 2023.3 allows authenticated low-privileged attackers to execute arbitrary JavaScript in the context of other users'…

CRITICAL 9.1EPSS 0.39%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.39%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

** exclusively-hosted-service ** A Stored Cross-Site Scripting (XSS) vulnerability in the chat functionality of the SelfBest platform 2023.3 allows authenticated low-privileged attackers to execute arbitrary JavaScript in the context of other users' sessions. This can be exploited to access administrative data and functions, leading to privilege escalation and full compromise of sensitive user data, as demonstrated by the ability to fetch and exfiltrate the contents of the /admin/users endpoint.

CVSS 3.1
9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS
0.39% probability · 33th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-79
Affected
selfbest/selfbest
Source
cve@mitre.org
EPSS trend
0%3%5%27 October 2026: 0.39%27 October 202627 October 2026

EPSS 0.4% since 27 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.