HashiCorp Vault CVE-2025-11621

Requires Vault's AWS Auth method to be configured so that the bound IAM principal (bound_iam_principal_arn) of a role is the SAME across multiple AWS accounts OR uses a wildcard, caused by mishandling of cache entries per HCSEC-2025-30. The attacker must possess valid AWS credentials for an IAM principal that matches that binding (PR:L), which limits exploitation to actors with some AWS foothold. Deployments using uniquely-scoped, per-account, non-wildcard bound principals are NOT exploitable, making this a non-default/misconfiguration-gated condition rather than a flaw against stock configurations. No user interaction is required (UI:N) and the Vault endpoint must be network-reachable to the attacker (AV:N).

Signals are mixed and point to a conditional, config-dependent flaw rather than a broadly exploitable one. The CVSS 3.1 vector (AV:N/AC:L/PR:L/UI:N/C:H/I:H/A:N, 8.1 HIGH) indicates a network-reachable attack needing only low privileges, with high confidentiality and integrity impact - consistent with an authentication bypass (CWE-288) that lets an attacker assume another identity in Vault. However, the description constrains exploitation to a specific misconfiguration: the bound_iam_principal of the AWS Auth method being identical across AWS accounts or using a wildcard, so AC:L arguably understates the real-world precondition. EPSS is low (0.49%, 41st percentile) and there is NO CISA KEV listing and NO public POC referenced - exploitation status is 'no public exploit identified at time of analysis.' The low EPSS is consistent with the targeted, misconfiguration-gated nature of the bug rather than mass exploitation. Net: this is a credible priority ONLY for organizations whose AWS Auth configuration matches the vulnerable pattern (shared/wildcard bound principals across accounts); for correctly-scoped single-account bindings the practical risk is substantially lower than the 8.1 score suggests. Verify your actual bound_iam_principal configuration before triaging as critical.

An attacker who controls AWS credentials for an IAM principal in one AWS account targets a Vault deployment whose AWS Auth role binds a principal ARN that is shared across accounts or uses a wildcard. By authenticating to Vault's AWS auth endpoint with their own matching principal, the attacker is granted the Vault identity and policies intended for a different account, bypassing the intended account isolation and reading secrets they should not access. No public exploit code has been identified; exploitation requires the specific vulnerable binding configuration plus valid AWS credentials (PR:L).