OpenBao is an open source identity-based secrets management system. Prior to version 2.5.3, `ExtractPluginFromImage()` in OpenBao's OCI plugin downloader extracts a plugin binary from a container image by streaming decompressed tar data via `io.Copy` with no upper bound on the number of bytes written. An attacker who controls or compromises the OCI registry referenced in the victim's configuration can serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file. The SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace **legit plugin image** with no need to change its signature. Version 2.5.3 contains a patch.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - OpenBao is an open source identity-based secrets management system. Prior to version 2.5.2, OpenBao does
    not prompt for user confirmation when logging in via JWT/OIDC and a role with `callback_mode` set to
    `direct`. This allows an attacker to start an authentication request and perform "remote phishing" by
    having the victim visit the URL and automatically log-in to the session of the attacker. Despite being
    based on the authorization code flow, the `direct` mode calls back directly to the API and allows an
    attacker to poll for an OpenBao token until it is issued. Version 2.5.2 includes an additional
    confirmation screen for `direct` type logins that requires manual user interaction in order to finish the
    authentication. This issue can be worked around either by removing any roles with `callback_mode=direct`
    or enforcing confirmation for every session on the token issuer side for the Client ID used by OpenBao.
    (CVE-2026-33757)

  - An authenticated user with access to a kvv2 path through a policy containing a glob may be able to delete
    secrets they were not authorized to read or write, resulting in denial-of-service. This vulnerability did
    not allow a malicious user to delete secrets across namespaces, nor read any secret data. Fxed in Vault
    Community Edition 2.0.0 and Vault Enterprise 2.0.0, 1.21.5, 1.20.10, and 1.19.16. (CVE-2026-3605)

  - Vault is vulnerable to a denial-of-service condition where an unauthenticated attacker can repeatedly
    initiate or cancel root token generation or rekey operations, occupying the single in-progress operation
    slot. This prevents legitimate operators from completing these workflows. This vulnerability,
    CVE-2026-5807, is fixed in Vault Community Edition 2.0.0 and Vault Enterprise 2.0.0. (CVE-2026-5807)

  - OpenBao is an open source identity-based secrets management system. Prior to version 2.5.2, OpenBao
    installations that have an OIDC/JWT authentication method enabled and a role with `callback_mode=direct`
    configured are vulnerable to XSS via the `error_description` parameter on the page for a failed
    authentication. This allows an attacker access to the token used in the Web UI by a victim. The
    `error_description` parameter has been replaced with a static error message in v2.5.2. The vulnerability
    can be mitigated by removing any roles with `callback_mode` set to `direct`. (CVE-2026-33758)

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-c7450bfed6 advisory.

    Update to upstream 2.5.3, fix CVE-2026-34986, CVE-2026-39388, CVE-2026-39396, CVE-2026-40264


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-2026-41918b2b57 advisory.

    Update to upstream 2.5.3, fix CVE-2026-34986, CVE-2026-39388, CVE-2026-39396, CVE-2026-40264


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 42 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-c008e6a5da advisory.

    Update to upstream 2.5.3, fix CVE-2026-34986, CVE-2026-39388, CVE-2026-39396, CVE-2026-40264


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.

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

  - OpenBao is an open source identity-based secrets management system. Prior to version 2.5.3,
    `ExtractPluginFromImage()` in OpenBao's OCI plugin downloader extracts a plugin binary from a container
    image by streaming decompressed tar data via `io.Copy` with no upper bound on the number of bytes written.
    An attacker who controls or compromises the OCI registry referenced in the victim's configuration can
    serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file. The
    SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is
    detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace
    **legit plugin image** with no need to change its signature. Version 2.5.3 contains a patch.
    (CVE-2026-39396)

ID	Name	Product	Family	Type	Severity
442269	Alpine: multiple openbao packages: security update to 2.5.4-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	Local	critical
442269	Alpine: multiple openbao packages: security update to 2.5.4-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	Local	critical
311376	Fedora 44 : openbao (2026-c7450bfed6)	Nessus	Fedora Local Security Checks	Local	low
311375	Fedora 43 : openbao (2026-41918b2b57)	Nessus	Fedora Local Security Checks	Local	low
311365	Fedora 42 : openbao (2026-c008e6a5da)	Nessus	Fedora Local Security Checks	Local	low
440688	SCA: security update for github.com/openbao/openbao (GHSA-r65v-xgwc-g56j)	Tenable Cloud Security	SCA Checks	Local	medium
440688	SCA: security update for github.com/openbao/openbao (GHSA-r65v-xgwc-g56j)	Tenable Self-Hosted Container Security	SCA Checks	Local	medium

Detections

Analytics

CVE-2026-39396

medium

Tenable Plugins

critical

critical

low

low

low

medium

medium