Description
Not a vulnerability. Creating a serial queue that overwrites cups-files.conf requires membership in SystemGroups (lpadmin), which is an opt-in cupsd admin role granted by a superuser. No privilege boundary is crossed.
Published: 2026-09-22
Score: 8.2 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Not a vulnerability. Creating a serial queue that overwrites cups-files.conf requires membership in SystemGroups (lpadmin), which is an opt-in cupsd admin role granted by a superuser. No privilege boundary is crossed.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • If serial printers are not required, remove the serial backend package file or change its permissions so cupsd no longer runs it as root, for example: chmod 0755 /usr/lib/cups/backend/serial.
  • Restrict membership of the lpadmin (and other SystemGroup) group to users who are already trusted with root‑equivalent access.
  • Leave FileDevice unset or set to No in /etc/cups/cups-files.conf.
  • Keep SELinux in enforcing mode; the cupsd_t domain may block some of the file writes used in this chain.

Generated by OpenCVE AI on September 22, 2026 at 09:52 UTC.

Tracking

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Advisories

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History

Tue, 22 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
References

Tue, 22 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
Description A privilege escalation vulnerability was found in CUPS when used with the cups-filters serial backend. A local user who is a member of the lpadmin group can configure a printer that uses a privileged serial backend. The CUPS scheduler does not restrict the path component of non-file device URIs, so the root-privileged backend can write attacker-controlled print data to an arbitrary file. This can be used to change security-sensitive CUPS configuration and ultimately achieve root code execution. Exploitation requires local lpadmin group membership and a serial backend binary installed with root-only permissions. Not a vulnerability. Creating a serial queue that overwrites cups-files.conf requires membership in SystemGroups (lpadmin), which is an opt-in cupsd admin role granted by a superuser. No privilege boundary is crossed.
CPEs cpe:/a:redhat:hummingbird:1
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat hummingbird
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Tue, 22 Sep 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 threat_severity

Important

Tue, 22 Sep 2026 08:45:00 +0000

Type Values Removed Values Added
Description A privilege escalation vulnerability was found in CUPS when used with the cups-filters serial backend. A local user who is a member of the lpadmin group can configure a printer that uses a privileged serial backend. The CUPS scheduler does not restrict the path component of non-file device URIs, so the root-privileged backend can write attacker-controlled print data to an arbitrary file. This can be used to change security-sensitive CUPS configuration and ultimately achieve root code execution. Exploitation requires local lpadmin group membership and a serial backend binary installed with root-only permissions.
Title Cups: cups-filters: cups-filters: lpadmin can escalate to root via privileged serial backend (cups2root)
First Time appeared Redhat
Redhat enterprise Linux
Redhat hummingbird
Weaknesses CWE-269
CPEs cpe:/a:redhat:hummingbird:1
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat hummingbird
References
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H'}

Subscriptions

No data.

cve-icon MITRE

Status: REJECTED

Assigner: redhat

Published:

Updated: 2026-09-22T14:19:13.126Z

Reserved: 2026-09-22T07:58:16.551Z

Link: CVE-2026-95511

cve-icon Vulnrichment

Updated: 2026-09-22T13:13:23.515Z

cve-icon NVD

Status : Rejected

Published: 2026-09-22T09:17:06.217

Modified: 2026-09-22T15:17:25.797

Link: CVE-2026-95511

cve-icon Redhat

Severity : Important

Publid Date: 2026-09-18T01:07:08Z

Links: CVE-2026-95511 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-22T10:00:15Z

Weaknesses
  • CWE-269

    Improper Privilege Management