CVE-2026-40541

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.48% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 39.4% of scored records. A rank, not a probability.

NVD base score

9.0 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

NVD analysis status

Received. NVD last modified this record on 2026-08-28.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-08-28 07:07Z23 HR AGO

Last updated

2026-08-28 11:44Z18 HR AGO

Reserved

2026-04-14

Assigning CNA

synology

Record state

PUBLISHED

Severity

Critical (CVSS 9.0)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

Weaknesses

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')Base

Data version

5.2

Document digest

4ed285ab681af88d2791a91499f766be6bda11d9cadc076f73bcc7d4c6ea033b

• www.synology.comSynology-SA-26:10 Synology Chat Serverhttps://www.synology.com/en-global/security/advisory/Synology_SA_26_10vendor-advisory