Use of a Broken or Risky Cryptographic Algorithm Affecting libcephfs-proxy2 package, versions *


Severity

Recommended
0.0
high
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.17% (7th percentile)

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  • Snyk IDSNYK-RHEL10-LIBCEPHFSPROXY2-18997283
  • published20 Aug 2026
  • disclosed19 Aug 2026

Introduced: 19 Aug 2026

NewCVE-2026-39944  (opens in a new tab)
CWE-327  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:10 libcephfs-proxy2.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libcephfs-proxy2 package and not the libcephfs-proxy2 package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

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 RADOS Gateway (RGW) protects STS session tokens with an AES-128-CBC handler that provides no message authentication, allowing an attacker who holds any valid STS token to tamper with it undetected and escalate to full RGW administrative access. Because the ciphertext is unauthenticated, the attacker can perform a CBC bit-flip on the acct_type, perm_type, and is_admin fields of their own token, and a forged is_admin value triggers a global administrative override that bypasses all capability checks. The attack is reachable remotely over the RGW S3 endpoint and is a self-contained modification of a token the attacker already possesses, requiring no encryption oracle and no network observation. It requires only a single valid STS token, which need not carry any elevated privileges, with STS enabled. This issue is fixed in versions 20.2.4 and 19.2.6.

CVSS Base Scores

version 3.1