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Fencer Vulns
high 7.8

CVE-2026-34990 json

OpenPrinting CUPS: Local print admin token disclosure using temporary printers

published 2026-04-03 7 mo ago modified 2026-07-24 3 mo ago also EUVD-2026-18889

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits
0
none known

Summary

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, a local unprivileged user can coerce cupsd into authenticating to an attacker-controlled localhost IPP service with a reusable Authorization: Local ... token. That token is enough to drive /admin/ requests on localhost, and the attacker can combine CUPS-Create-Local-Printer with printer-is-shared=true to persist a file:///... queue even though the normal FileDevice policy rejects such URIs. Printing to that queue gives an arbitrary root file overwrite; the PoC below uses that primitive to drop a sudoers fragment and demonstrate root command execution. At time of publication, there are no publicly available patches.

Patch / fix

  • cups Debian 14 2.4.17-1

debian advisories DEBIAN-CVE-2026-34990

  • cups Ubuntu 22.04 LTS 2.4.1op1-1ubuntu4.20
  • cups Ubuntu 24.04 LTS 2.4.7-1.2ubuntu7.13
  • cups Ubuntu 25.10 2.4.12-0ubuntu3.9
  • cups Ubuntu 26.04 LTS 2.4.16-1ubuntu1.2

ubuntu advisories UBUNTU-CVE-2026-34990

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • cups hummingbird 1 2.4.17-1.hum1
  • cups-lpd hummingbird 1 2.4.17-1.hum1
  • cups-libs hummingbird 1 2.4.17-1.hum1
  • cups-client hummingbird 1 2.4.17-1.hum1
  • cups-ipptool hummingbird 1 2.4.17-1.hum1
  • cups-filesystem hummingbird 1 2.4.17-1.hum1
  • cups-printerapp hummingbird 1 2.4.17-1.hum1

red hat advisories RHSA-2026:8814

  • cups SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +14 more 2.2.7-150000.3.86.1
  • cups SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 1.7.5-20.62.1

suse advisories SUSE-SU-2026:1617-1SUSE-SU-2026:1399-1

  • cups openSUSE Tumbleweed 2.4.17-1.1

opensuse advisories openSUSE-SU-2026:10589-1

  • cups Alpine 3.24, Alpine 3.23, Alpine 3.22 +2 more 2.4.18-r0

alpine advisories ALPINE-CVE-2026-34990

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • cups Azure Linux 3.0 2.4.17-1

azure linux advisories AZL-81825

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-34990 updated cvss 5.2

cups: OpenPrinting CUPS: Privilege escalation via arbitrary file overwrite due to coerced authentication

  • Red Hat Enterprise Linux 6 cups, cups-lpd, cups-php, cups-libs Red Hat Enterprise Linux 7 cups, cups-lpd, cups-libs, cups-client, cups-ipptool, cups-filesystem
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 cups, cups-lpd, cups-libs, cups-client, cups-ipptool, cups-filesystem Red Hat Enterprise Linux 9 cups, cups-lpd, cups-libs, cups-client, cups-ipptool, cups-filesystem, +1 more Red Hat Enterprise Linux 10 cups Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images cups 2.4.17-1.hum1, cups-lpd 2.4.17-1.hum1, cups-libs 2.4.17-1.hum1, cups-client 2.4.17-1.hum1, cups-ipptool 2.4.17-1.hum1, cups-filesystem 2.4.17-1.hum1, +1 more
    fixed: vendor fix RHSA-2026:8814

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
7 mo ago

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/OpenPrinting/cups/security/advisories/GHSA-c54j-2vqw-wpwp referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 5.0 CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:H/SI:H/SA:L
CISA ADP 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 4.0 5.0 CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:H/SI:H/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • OpenPrinting cups

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.