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Fencer Vulns
medium 5.5

CVE-2026-4897 json

Polkit: polkit: denial of service via unbounded input processing through standard input

published 2026-03-26 7 mo ago modified 2026-11-05 3 d ago also EUVD-2026-16214

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

A flaw was found in polkit. A local user can exploit this by providing a specially crafted, excessively long input to the `polkit-agent-helper-1` setuid binary via standard input (stdin). This unbounded input can lead to an out-of-memory (OOM) condition, resulting in a Denial of Service (DoS) for the system.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 0:125-4.el10_2.1
  • Red Hat Red Hat Hardened Images 127-5.1.hum1
  • policykit-1 Debian 14 127-3

debian advisories DEBIAN-CVE-2026-4897

  • policykit-1 Ubuntu 22.04 LTS 0.105-33ubuntu0.1
  • policykit-1 Ubuntu 24.04 LTS 124-2ubuntu1.24.04.3
  • policykit-1 Ubuntu 25.10 126-2ubuntu0.1

ubuntu advisories UBUNTU-CVE-2026-4897

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

  • polkit hummingbird 1 127-5.1.hum1
  • polkit-libs hummingbird 1 127-5.1.hum1
  • polkit RHEL 10.2 125-4.el10_2.1
  • polkit-libs RHEL 10.2 125-4.el10_2.1

red hat advisories RHSA-2026:66287RHSA-2026:59997

  • polkit SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 123-160000.3.1
  • polkit SLE Module for Basesystem 15 SP7, SLE Micro 5.5, openSUSE Leap 15.6 121-150500.3.11.1
  • polkit Linux Micro 6.0 121-4.1
  • expat Linux Micro 6.2 2.7.1-160000.5.1
  • polkit Linux Micro 6.1 121-slfo.1.1_3.1
  • polkit SLES LTSS Extended Security 12 SP5 0.113-5.35.1

suse advisories SUSE-SU-2026:22054-1SUSE-SU-2026:22090-1SUSE-SU-2026:1425-1SUSE-SU-2026:1424-1SUSE-SU-2026:20969-1SUSE-SU-2026:21032-1

  • polkit openSUSE Leap 16.0 123-160000.3.1
  • polkit openSUSE Tumbleweed 127-3.1

opensuse advisories openSUSE-SU-2026:20925-1openSUSE-SU-2026:10453-1

  • polkit AlmaLinux 10 125-4.el10_2.1
  • polkit-libs AlmaLinux 10 125-4.el10_2.1

almalinux advisories ALSA-2026:59997

  • polkit Rocky Linux 10 125-4.el10_2.1

rocky linux advisories RLSA-2026:59997

  • polkit Azure Linux 3.0 123-4

azure linux advisories AZL-81558

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-2026-4897 updated cvss 5.5

polkit: Polkit: Denial of Service via unbounded input processing through standard input

  • Red Hat Enterprise Linux 6 polkit, polkit-desktop-policy Red Hat Enterprise Linux 7 polkit Red Hat Enterprise Linux 8 polkit, polkit-libs
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux 9 polkit, polkit-libs
    affected: workaround, no fix available
  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux AppStream (v. 10) polkit-docs 125-4.el10_2.1, polkit-devel 125-4.el10_2.1, polkit-debuginfo 125-4.el10_2.1, polkit-debugsource 125-4.el10_2.1, polkit-libs-debuginfo 125-4.el10_2.1 Red Hat Enterprise Linux BaseOS (v. 10) polkit 125-4.el10_2.1, polkit-libs 125-4.el10_2.1
    fixed: vendor fix RHSA-2026:59997
  • Red Hat Hardened Images polkit 127-5.1.hum1, polkit-libs 127-5.1.hum1
    fixed: vendor fix RHSA-2026:66287

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
none
Automatable
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Hardened Images
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat OpenShift Container Platform 4

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

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.