What’s Vulnerable › Vulnerabilities

CVE-2026-87876: Cups: openprinting cups: remaining case-insensitive username matching in scheduler side paths (cve-2026-27447 follow-up)

• Severity: low (CVSS 3.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-09 · updated 2026-10-21
• Weakness: CWE-178

Description

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.

Affected products

• Red Hat OpenShift Container Platform 4.18: all versions
• Red Hat Enterprise Linux 10: all versions
• Red Hat Enterprise Linux 6: all versions
• Red Hat Enterprise Linux 7: all versions
• Red Hat Enterprise Linux 8: all versions
• Red Hat Enterprise Linux 9: all versions
• Red Hat Hardened Images: all versions — fixed in 2.4.19-4.2.hum1

How to fix

Upgrade to a fixed version: Red Hat Hardened Images 2.4.19-4.2.hum1. Check the vendor advisory for mitigations.

References

• https://access.redhat.com/errata/RHSA-2026:67568
• https://access.redhat.com/security/cve/CVE-2026-87876
• https://bugzilla.redhat.com/show_bug.cgi?id=2530991
• https://github.com/OpenPrinting/cups/commit/88e67c00c130a45f3a1edf36686f7a0b2982fef8
• https://github.com/OpenPrinting/cups/commit/f56844dbe4a54a9f8e1aeb3b913fbee614156bdb
• https://github.com/OpenPrinting/cups/security/advisories/GHSA-r8jp-q6fh-g5r2
• https://github.com/OpenPrinting/cups/security/advisories/GHSA-r8jp-q6fh-g5r2

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