---
id: CVE-2025-30156
title: >-
  Ceph is an open-source distributed storage platform providing object, block,
  and file storage
summary: >-
  Ceph is an open-source distributed storage platform providing object, block,
  and file storage. In versions prior to 20.2.4 and 19.2.6, the CephX
  authentication protocol encrypts tickets with AES-128-CBC in an
  unauthenticated mode that us…
severity: high
cvss: 8.9
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L'
cwe:
  - CWE-327
  - CWE-1204
published: '2026-08-28'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T21:11:56.250'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-30156'
references:
  - url: >-
      https://github.com/ceph/ceph/commit/2ba086255de09c8b95177717cc7e9dd4377e2f0f
    label: security-advisories@github.com
  - url: >-
      https://github.com/ceph/ceph/commit/3078188a7bdd89e2975280f2a906c71c2f6effd6
    label: security-advisories@github.com
  - url: 'https://github.com/ceph/ceph/security/advisories/GHSA-7q3q-3975-qw3q'
    label: security-advisories@github.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-30156.json
  - url: 'https://access.redhat.com/security/cve/CVE-2025-30156'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2393864'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2025-30156'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-30156'
  - url: 'https://access.redhat.com/errata/RHSA-2026:18134'
  - url: 'https://access.redhat.com/errata/RHSA-2026:18587'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
epss: 0.00093
epssPercentile: 0.00643
ingestedAt: '2026-09-08T22:12:30.941Z'
vendor: Red Hat
product: Red Hat Enterprise Linux BaseOS (v. 10)
affected:
  - ceph_storage 7
  - ceph_storage 8
  - enterprise_linux 8
  - openshift_data_foundation 4
  - enterprise_linux_appstream_v_10
  - enterprise_linux_appstream_v_9
  - enterprise_linux_baseos_v_10
  - enterprise_linux_baseos_v_9
  - enterprise_linux_codeready_linux_builder_v_10
  - enterprise_linux_codeready_linux_builder_v_9
  - enterprise_linux_real_time_for_nfv_v_10
  - enterprise_linux_real_time_for_nfv_v_9
  - enterprise_linux_real_time_v_10
  - enterprise_linux_real_time_v_9
patched:
  - enterprise_linux_appstream_v_10
  - enterprise_linux_appstream_v_9
  - enterprise_linux_baseos_v_10
  - enterprise_linux_baseos_v_9
  - enterprise_linux_codeready_linux_builder_v_10
  - enterprise_linux_codeready_linux_builder_v_9
  - enterprise_linux_real_time_for_nfv_v_10
  - enterprise_linux_real_time_for_nfv_v_9
  - enterprise_linux_real_time_v_10
  - enterprise_linux_real_time_v_9
scores:
  nvd: 8.9
  vendor: 8.7
---

## Overview

Ceph is an open-source distributed storage platform providing object, block, and file storage. In versions prior to 20.2.4 and 19.2.6, the CephX authentication protocol encrypts tickets with AES-128-CBC in an unauthenticated mode that uses a hard-coded initialization vector and no message authentication, allowing an attacker to forge credentials and gain cluster-wide access. Because the ciphertext is malleable and the monitor will encrypt attacker-chosen entity names, an attacker holding one low-privilege key and able to observe CephX traffic can use the monitor as an encryption oracle and splice ciphertext blocks into valid tickets for privileged entities such as Manager, MDS, and OSD. The same lack of authentication also lets an attacker with CephX permissions escalate privileges by flipping a single bit in a service ticket to set its allow_all field to true. This issue is fixed in versions 20.2.4 and 19.2.6.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **RHSA-2026:18134** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), Red Hat Enterprise Linux Real Time (v. 10) · released 2026-05-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:18134)
- **RHSA-2026:18587** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-05-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:18587)
- **Red Hat VEX** · Important · affected: Red Hat Ceph Storage 7, Red Hat Ceph Storage 8, Red Hat Enterprise Linux 8, Red Hat Openshift Data Foundation 4 · no fix planned: Red Hat Ceph Storage 7, Red Hat Ceph Storage 8, Red Hat Enterprise Linux 8, Red Hat Openshift Data Foundation 4 · updated 2026-09-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-30156.json)