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.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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. (CVE-2026-39944)

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:79101 advisory.

    Red Hat Ceph Storage is a scalable, open, software-defined storage platform that combines the most stable     version of the Ceph storage system with a Ceph management platform, deployment utilities, and support     services.

    These new packages include numerous security and bug fixes. Space precludes documenting all of these     changes in this advisory. Users are directed to the Red Hat Ceph Storage Release Notes for information on     the most significant of these changes:

    https://docs.redhat.com/en/documentation/red_hat_ceph_storage/8/html/8.1_release_notes

    ==========================================     IMPORTANT:
    The Red Hat Ceph Storage team has migrated our defect tracking from Bugzilla to an internal Jira system.
    Bug fixes and CVE information that was previously listed in the errata releases are now listed in the     Release Notes.

    Refer to the release notes going forward for the latest and most accurate fix and CVE information.
    ==========================================

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the TSSA-2026:1003 advisory.

    Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

    CVE-2026-50152:
    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 Monitor subscription handler fails to properly authorize access to the     configuration-key store, allowing any CephX user with only 'mon allow r' capabilities to read the entire     store by sending a single crafted MMonSubscribe message. The config-key store holds sensitive secrets     including OSD LUKS disk-encryption passphrases and, on cephadm-managed clusters, the SSH private key that     cephadm uses to reach every host in the cluster. Because that key grants root on every node under the     default cephadm configuration, a low-privileged read-only account can escalate to full cluster and host     compromise. This issue is fixed in versions 20.2.4 and 19.2.6

    CVE-2026-39944:
    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.

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-7de7d03796 advisory.

    # Ceph 20.2.4 GA

    * CVE-2025-30156 is an authentication bypass in CephX caused by misuse of AES-CBC.
    >    https://docs.ceph.com/en/latest/security/CVE-2025-30156
    * CVE-2026-39944 shares the unauthenticated-encryption root cause of CVE-2025-30156     >    https://docs.ceph.com/en/latest/security/CVE-2026-39944
    * CVE-2026-50152 is an improper authorization flaw in the Ceph Monitor subscription handler.
    >    https://docs.ceph.com/en/latest/security/CVE-2026-50152
    * CVE-2026-54330 is a flaw in RGW not properly verifying its SigV4 cryptographic signatures in RGW's SigV4     verifier.
    >    https://docs.ceph.com/en/latest/security/CVE-2026-54330



Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-ebffec502b advisory.

    # Ceph 19.2.6 GA

    * CVE-2025-30156 is an authentication bypass in CephX caused by misuse of AES-CBC.
    >    https://docs.ceph.com/en/latest/security/CVE-2025-30156
    * CVE-2026-39944 shares the unauthenticated-encryption root cause of CVE-2025-30156     >    https://docs.ceph.com/en/latest/security/CVE-2026-39944
    * CVE-2026-50152 is an improper authorization flaw in the Ceph Monitor subscription handler.
    >    https://docs.ceph.com/en/latest/security/CVE-2026-50152
    * CVE-2026-54330 is a flaw in RGW not properly verifying its SigV4 cryptographic signatures in RGW's SigV4     verifier.
    >    https://docs.ceph.com/en/latest/security/CVE-2026-54330


Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2026-39944)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
478671	Echo: ceph: security update to 20.2.4+ds-1	Tenable Cloud Security	Echo Local Security Checks	Local	high
478671	Echo: ceph: security update to 20.2.4+ds-1	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	high
369296	RHEL 9 : Red Hat Ceph Storage 8.1 (RHSA-2026:79101)	Nessus	Red Hat Local Security Checks	Local	medium
346443	TencentOS Server 4: ceph (TSSA-2026:1003)	Nessus	Tencent Local Security Checks	Local	critical
338829	Fedora 44 : ceph (2026-7de7d03796)	Nessus	Fedora Local Security Checks	Local	critical
338789	Fedora 43 : ceph (2026-ebffec502b)	Nessus	Fedora Local Security Checks	Local	critical
338274	Linux Distros Unpatched Vulnerability : CVE-2026-39944	Nessus	Misc.	Local	high

Detections

Analytics

CVE-2026-39944

high

Tenable Plugins

high

high

medium

critical

critical

critical

high