CVE-2026-65638 Vulnerability Analysis & Exploit Intelligence

Improper escaping of a request URL in ConfigServer Security & Firewall allows an unauthenticated remote attacker to execute arbitrary commands as the CSF service account via shell command injection. The vulnerability affects versions of the software originally distributed by ConfigServer, as well as versions of the WebPros-maintained fork that contain the vulnerable code. WebPros has addressed the vulnerability in version 16.30. Other forks or independently maintained versions of ConfigServer Security & Firewall (CSF) may also be affected and should be evaluated independently.

Published Sep 10, 2026Updated Sep 10, 2026Sources: cvelistV5, hackerone

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

chance of exploitation in 30 days

Affects

webpros

configserver_security_firewall

CVSS base

9.2

CRITICAL

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Affected scope

The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.

Vendors (2)

webpros configserver

Products (1)

configserver security firewall

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
9.2	CVSS 4.0	CRITICAL	—	—	cvelistV5

Weakness & attack patterns

CWE-78

References

1 on the record

support.cpanel.net/hc/en-us/articles/43387915588375-Security-CVE-2026-65638-CSF-Security-Release
reference

Elsewhere on this site

webprosevery CVE for this vendor
configserverevery CVE for this vendor
CWE-78other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.