What’s Vulnerable › Vulnerabilities

CVE-2026-27447: OpenPrinting CUPS: Authorization bypass via case-insensitive group-member lookup

• Severity: medium (CVSS 6.3 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: yes
• Published: 2026-04-03 · updated 2026-07-24
• Weakness: CWE-863

Description

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, CUPS daemon (cupsd) contains an authorization bypass vulnerability due to case-insensitive username comparison during authorization checks. The vulnerability allows an unprivileged user to gain unauthorized access to restricted operations by using a user with a username that differs only in case from an authorized user. At time of publication, there are no publicly available patches.

Affected products

• OpenPrinting cups: through 2.4.16

References

• https://github.com/OpenPrinting/cups/commit/88516bf6d9e34cef7a64a704b856b837f70cd220
• https://github.com/OpenPrinting/cups/security/advisories/GHSA-v987-m8hp-phj9

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