SB2026082178 - Fedora 44 update for ceph



SB2026082178 - Fedora 44 update for ceph

Published: August 21, 2026

Security Bulletin ID SB2026082178
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Privilege escalation

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 vulnerabilities.


1) Use of a broken or risky cryptographic algorithm (CVE-ID: CVE-2025-30156)

CWE-ID: CWE-327 - Use of a Broken or Risky Cryptographic Algorithm

CVSSv4: 8.6 [CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to bypass authentication and gain cluster-wide access.

The vulnerability exists due to use of a broken or risky cryptographic algorithm in the CephX authentication implementation when processing CephX tickets over the network. A remote user can manipulate observed ciphertext and forge credentials to bypass authentication and gain cluster-wide access.

Exploitation requires a low-privilege CephX key and the ability to observe CephX ciphertext on the local network.


2) Improper Verification of Cryptographic Signature (CVE-ID: CVE-2026-39944)

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

CVSSv4: 7.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to escalate privileges to full RGW administrative access.

The vulnerability exists due to improper verification of a cryptographic signature in RGW STS session tokens when processing a valid STS token. A remote user can tamper with a token using CBC bit-flipping to escalate privileges to full RGW administrative access.

Exploitation requires STS to be enabled and a single valid STS token already held by the attacker.


3) Improper Authorization (CVE-ID: CVE-2026-50152)

CWE-ID: CWE-285 - Improper Authorization

CVSSv4: 7 [CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to disclose sensitive information.

The vulnerability exists due to improper authorization in the Monitor subscription handler when handling a crafted MMonSubscribe message. A remote user can send a single crafted MMonSubscribe message to disclose sensitive information.

Exploitation requires access to the cluster and a compromised account with mon allow r caps. On cephadm-managed clusters, exposed data may include the SSH private key used by cephadm to reach hosts.


4) Improper Verification of Cryptographic Signature (CVE-ID: CVE-2026-54330)

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

CVSSv4: 7.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to escalate privileges.

The vulnerability exists due to improper verification of cryptographic signatures in Ceph RGW\'s SigV4 handler when processing presigned PUT requests. A remote user can attach arbitrary unsigned x-amz-* headers to escalate privileges.

Exploitation requires a presigned PUT URL.


Remediation

Install update from vendor's website.