CVE-2026-27447
OpenPrinting CUPS: Authorization bypass via case-insensitive group-member lookup
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.
INFO
Published Date :
April 3, 2026, 10:16 p.m.
Last Modified :
April 22, 2026, 4:20 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Monitor for vendor release of security patches.
- Apply vendor patches when available.
- Restrict access to authorized users and operations.
Public PoC/Exploit Available at Github
CVE-2026-27447 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-27447.
| URL | Resource |
|---|---|
| https://github.com/OpenPrinting/cups/commit/88516bf6d9e34cef7a64a704b856b837f70cd220 | Patch |
| https://github.com/OpenPrinting/cups/security/advisories/GHSA-v987-m8hp-phj9 | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-27447 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-27447
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
CVE's I found. technical writeups, expolitation examples and fuzzing sessions walkthroughs
cve open-source-security vulnerability
GDB Python C
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-27447 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-27447 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 22, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N Added CPE Configuration OR *cpe:2.3:a:openprinting:cups:*:*:*:*:*:*:*:* versions up to (including) 2.4.16 Added Reference Type GitHub, Inc.: https://github.com/OpenPrinting/cups/commit/88516bf6d9e34cef7a64a704b856b837f70cd220 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/OpenPrinting/cups/security/advisories/GHSA-v987-m8hp-phj9 Types: Exploit, Vendor Advisory -
New CVE Received by [email protected]
Apr. 03, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:L/A:N Added CWE CWE-863 Added Reference https://github.com/OpenPrinting/cups/commit/88516bf6d9e34cef7a64a704b856b837f70cd220 Added Reference https://github.com/OpenPrinting/cups/security/advisories/GHSA-v987-m8hp-phj9