4.3

CVE-2026-9491: synology synology chat server Server-Side Request Forgery (SSRF)

CVSS: 4.3v3.1MediumUndergoing analysis
Published 28-08-2026Last modified 28-08-2026
Open JSON

Vulnerability summary

CVE-2026-9491 is a medium (CVSS 4.3) Server-Side Request Forgery (SSRF) vulnerability in synology synology chat server. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28% of scored vulnerabilities.

Overall risk
17/100
0100
Low · default modelHow is this calculated?
CVSS score
4.3/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.36%
0%100%
Low · -0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 28-08-2026
    PublishedVulnerability first disclosed.
  2. 28-08-2026
    Last modifiedVulnerability information updated.

Description

A server-ide request forgery (SSRF) vulnerability in webhook in Synology Chat Server before 2.4.5-22148 allows remote authenticated users to obtain non-sensitive information.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.36%

Chance of exploitation in the next 30 days

Percentile

28%

Versus all other CVEs

30-day change

-0.04 pp

From 0.40% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.36%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Synology1 product

1 vendor · 1 product

References

1 links