Vault Enterprise CVE-2026-105820

Requires Vault ENTERPRISE with namespaces configured and in use - Community Edition does not support namespaces and is explicitly not affected. The attacker must possess a valid authenticated token (PR:L) that is or can be assigned a specially crafted policy name containing path-traversal constructs; the vulnerable ACL policy cache then resolves that name against a different (including root) namespace. Limiting factors: enterprise-only feature dependency, multi-namespace configuration must be present, authentication is required, and the actual capabilities gained depend on which policies exist in the traversed namespace. Deployments running the fixed versions (2.1.2, 1.21.12, 1.20.17, 1.19.23) are not exploitable.

This is a moderate-priority, authenticated privilege-escalation flaw rather than a critical mass-exploitation threat. The CVSS 3.1 vector (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N, base 5.4) indicates a network-reachable, low-complexity issue that nonetheless requires some level of existing authenticated privilege (PR:L) - specifically a token that can be assigned crafted policy names. There is no EPSS score, no CISA KEV listing, and no public POC provided in the input, so all three exploitation-likelihood signals are either absent or negative; per precision rules this is 'no public exploit identified at time of analysis.' The real-world severity is arguably understated by the C:L/I:L rating: the description states a token can obtain the capabilities of policies in OTHER namespaces INCLUDING the root namespace, which in a multi-tenant Vault deployment is a serious cross-tenant/namespace authorization-boundary bypass that could, depending on the targeted policies, grant far-reaching secret access. The vendor nonetheless scored confidentiality/integrity as Low, so there is some tension between the described root-namespace reach and the assigned impact metrics - defenders managing sensitive multi-namespace Vault installations should treat this closer to a high-impact boundary bypass than the 5.4 base implies. Mitigating factors: exploitation is limited to Vault Enterprise with namespaces in use, requires an already-authenticated token, and Community Edition is explicitly unaffected.

A low-privileged tenant in a multi-namespace Vault Enterprise deployment obtains or is assigned a policy whose name embeds path-traversal constructs (e.g. '../'), causing the ACL policy cache to resolve it against another namespace. Using that token, the attacker then exercises capabilities belonging to policies in a different namespace - potentially the root namespace - to read or modify secrets outside their authorized tenant. No public exploit code was identified in the provided data; exploitation requires authenticated access (PR:L) but low complexity over the network.