Review reviewHigh

CVE-2026-67599

ClearFoundation ClearOS

ClearOS 7.9 contains an OS command injection vulnerability in the Log Viewer component that allows authenticated attackers to execute arbitrary commands by submitting unsanitized input through the filter parameter, which is interpolated directly into a shell command in File.php. Attackers can inject command substitution payloads into the filter parameter to execute arbitrary commands as the webconfig user, and due to extensive NOPASSWD sudo privileges granted to that user by default, immediately escalate to root.

CVSS
8.6
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.08.04
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 8.6

Vulnerability overview

ClearOS 7.9 contains an OS command injection vulnerability in the Log Viewer component that allows authenticated attackers to execute arbitrary commands by submitting unsanitized input through the filter parameter, which is interpolated directly into a shell command in File.php. Attackers can inject command substitution payloads into the filter parameter to execute arbitrary commands as the webconfig user, and due to extensive NOPASSWD sudo privileges granted to that user by default, immediately escalate to root.

Affected product and versions

Product
ClearFoundation ClearOS
Affected versions
>= 7.9
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that ClearFoundation ClearOS and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE
CWE-78