CVE-2026-87876 PUBLISHED

Cups: openprinting cups: remaining case-insensitive username matching in scheduler side paths (cve-2026-27447 follow-up)

Assigner: redhat
Reserved: 09.09.2026 Published: 09.09.2026 Updated: 09.09.2026

Two case-insensitive comparisons on request-derived usernames outside the main authorization path in CUPS's scheduler (printer ACL validation and private-attribute filtering) could allow bypass of username-based access controls in certain configurations.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
CVSS Score: 3

Attack Vector	Adjacent Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	Low	Integrity Impact	None
User Interaction	Required	Availability Impact	None

CVSS 3.1

Product Status

Vendor	Red Hat
Product	Red Hat Enterprise Linux 10
Versions	Default: affected

Vendor	Red Hat
Product	Red Hat Enterprise Linux 6
Versions	Default: affected

Vendor	Red Hat
Product	Red Hat Enterprise Linux 7
Versions	Default: affected

Vendor	Red Hat
Product	Red Hat Enterprise Linux 8
Versions	Default: affected

Vendor	Red Hat
Product	Red Hat Enterprise Linux 9
Versions	Default: affected

Vendor	Red Hat
Product	Red Hat Enterprise Linux 9
Versions	Default: affected

Vendor	Red Hat
Product	Red Hat Hardened Images
Versions	Default: affected

Vendor	Red Hat
Product	Red Hat OpenShift Container Platform 4
Versions	Default: affected

Workarounds

Fixed on upstream master branch with commit f56844d and for versions 2.4.x with commit 88e67c0.

Credits

Red Hat would like to thank arbor-s (Independent Security Researcher) for reporting this issue.

References

Problem Types

Improper Handling of Case Sensitivity CWE