CVE Tools
Sign in

CVE-2026-27447

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

Published: Apr 3, 2026Updated: Apr 22, 2026 Sources: CVE List NVD BDUCWE-863
4.8MEDIUM
NVD MITRE
EPSS Score
0.3%
Top 76.6%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:HPR:HUI:RS:UC:HI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:HPrivileges Required
High
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:LIntegrity
Low
A:NAvailability
None
Open in CVSS calculator →

Weaknesses

CWE-863

Affected Products

OpenPrinting
oss-projectaka cups, cups-filters, libcupsfilters
cupsOn-prem
OSS Libraries / generic-library
АО «ИВК»
commercial·RUaka ivk
АЛЬТ СП 10On-premOS
Operating Systems / linux-distro
Сообщество свободного программного обеспечения
oss-projectaka fsf
CUPS
Operating Systems / unix-bsd
and 1 more affected products View all →

Exploitability

Official Patch Available
Is your org exposed to CVE-2026-27447?We can run the check for you — a free external exposure review, no install. Check my exposure

Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

2 techniques
Initial Access
View detailed technique mapping

References

https://github.com/OpenPrinting/cups/commit/88516bf6d9e34cef7a64a704b856b837f70cd220
github.com
https://github.com/OpenPrinting/cups/security/advisories/GHSA-v987-m8hp-phj9
github.com
https://altsp.su/obnovleniya-bezopasnosti/
altsp.su
News mentions
Could not load news mentions.

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-27447 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows