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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
NVD MITRE
4.8CVSSMEDIUM
EPSS Score
0.3%
Top 76.8%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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.

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

cupsOpenPrinting
On-prem
OSS Libraries / generic-library
cupsopenprinting
On-prem
OSS Libraries / generic-library
АЛЬТ СП 10АО «ИВК»
On-premOS
Operating Systems / linux-distro
CUPSСообщество свободного программного обеспеченияOperating Systems / unix-bsd
openprintingoss-projectOSS Librariesaka cups, cups-filters, libcupsfilters
ао «ивк»commercialRUOperating Systemsaka ivk
сообщество свободного программного обеспеченияoss-projectOperating Systemsaka сообщество свободного программного обеспечения, fsf

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Official Patch Available

MITRE ATT&CK

2 techniques
Initial Access
View detailed technique mapping

References

https://github.com/OpenPrinting/cups/security/advisories/GHSA-v987-m8hp-phj9
github.com
https://github.com/OpenPrinting/cups/commit/88516bf6d9e34cef7a64a704b856b837f70cd220
github.com
https://altsp.su/obnovleniya-bezopasnosti/
altsp.su

Timeline

Published
Apr 3, 2026
Last Updated
Apr 22, 2026

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