Vulnerability · Published Apr 3, 2026 · Assigned by GitHub_M
CVE-2026-27447OpenPrinting CUPS: Authorization bypass via case-insensitive group-member lookup
Medium 4.8
In plain English
A medium-severity incorrect authorization in cups from OpenPrinting. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | cups | 2.4.18-r0 | ALPINE-CVE-2026-27447 |
| Alpine:v3.21 | cups | 2.4.18-r0 | ALPINE-CVE-2026-27447 |
| Alpine:v3.22 | cups | 2.4.18-r0 | ALPINE-CVE-2026-27447 |
| Alpine:v3.23 | cups | 2.4.18-r0 | ALPINE-CVE-2026-27447 |
| Alpine:v3.24 | cups | 2.4.18-r0 | ALPINE-CVE-2026-27447 |
| Debian:12 | cups | no fix listed | DEBIAN-CVE-2026-27447 |
| Debian:13 | cups | no fix listed | DEBIAN-CVE-2026-27447 |
| Debian:14 | cups | 2.4.17-1 | DEBIAN-CVE-2026-27447 |
| Ubuntu:22.04:LTS | cups | 2.4.1op1-1ubuntu4.20 | USN-8405-1 |
| Ubuntu:22.04:LTS | cups | 2.4.1op1-1ubuntu4.20 | UBUNTU-CVE-2026-27447 |
| Ubuntu:24.04:LTS | cups | 2.4.7-1.2ubuntu7.13 | USN-8405-1 |
| Ubuntu:24.04:LTS | cups | 2.4.7-1.2ubuntu7.13 | UBUNTU-CVE-2026-27447 |
| Ubuntu:25.10 | cups | 2.4.12-0ubuntu3.9 | USN-8405-1 |
| Ubuntu:25.10 | cups | 2.4.12-0ubuntu3.9 | UBUNTU-CVE-2026-27447 |
| Ubuntu:26.04:LTS | cups | 2.4.16-1ubuntu1.2 | UBUNTU-CVE-2026-27447 |
| Ubuntu:26.04:LTS | cups | 2.4.16-1ubuntu1.2 | USN-8405-1 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| OpenPrinting | cups | <= 2.4.16 |
Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:L/A:N