The vulnerability is an authorization bypass in the Vault secrets back-end of Juju. An authenticated unit agent can update secret revisions that it is not permitted to modify. This can lead to poisoning of any existing secret revision within the affected Vault secret back-end, compromising data integrity and potentially enabling misconfigurations or denial of service. The weakness is classified as CWE‑285 (Authorization Bypass Through Privileged Credential).

Affected products are Canonical Juju, versions 3.1.6 through 3.6.18. Only these releases are impacted, as newer releases contain the fix.

The CVSS score is 7.6, indicating high severity, but the EPSS score is below 1% suggesting a low likelihood of exploitation in the wild. The vulnerability is not listed in the CISA KEV catalog. Exploitation requires that an attacker has an authenticated unit agent in the Juju environment; once achieved, the attacker can modify secrets within that back-end, potentially undermining infrastructure security. The likely attack vector is an authenticated internal or remote agent attack, inferred from the need for a unit agent.