Summary
OpenBao's System Backend allows Unauthorized Management of the containing Namespace
A user that is granted namespace management (/sys/namespaces) capabilities within a non-root namespace ("the victim namespace") can abuse special handling of the literal path "root" in namespace path canonicalization to manage the victim namespace itself.
Details
Several endpoints under /sys/namespaces/* accept a namespace path segment that is canonicalized and then appended to the path of the sys mount's containing namespace (set via path prefix or X-Vault-Namespace header) to determine the absolute path of the namespace to operate on.
Given the special namespace path "root" canonicalizes to en empty path (""), when passed as /sys/namespaces/root, the resulting absolute namespace path remains equal to the sys mount's containing namespace. Given ACLs are evaluated before namespace path canonicalization, this allows users with capabilities on /sys/namespaces/root within any given namespace to operate on the namespace itself instead.
PoC
Start a development server:
bao server -dev
Create a namespace:
bao namespace create victim
This will be the namespace we gain unauthorized management of.
Create a policy that allows management of namespaces, inside of the victim
namespace.
bao policy write -namespace=victim namespace-management - <<EOF
path "sys/namespaces/*" {
capabilities = ["read", "update", "patch", "delete"]
}
EOF
Then create a token with above policy attached:
export BAO_TOKEN=$(bao token create -namespace=victim -policy=namespace-management -field=token)
Operate on the victim's namespace using the token, for example by outright deleting it:
bao namespace delete -namespace=victim root
Impact
Users that were granted the required capabilities can abuse this vulnerability to:
- Look up
- Delete
- Lock
- Patch custom metadata
against the namespace containing the system backend they can manage sys/namespaces/root in. The exact range of operations that can be performed depends on the specific capabilities granted on said path and any sub-paths such as /api-lock.
Notably, the root namespace is immutable and cannot be modified, deleted or locked, and is thus unaffected. Also note that users can only abuse this vulnerability to operate on the direct parent or "containing" namespace relative to their capabilities, not arbitrary namespaces.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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This will be fixed in OpenBao v2.5.5.
Frequently Asked Questions
- What is CVE-2026-55775? CVE-2026-55775 is a low-severity security vulnerability in github.com/openbao/openbao (go), affecting versions < 0.0.0-20260617103935-d3c1cc64b1ae. It is fixed in 0.0.0-20260617103935-d3c1cc64b1ae.
- Which versions of github.com/openbao/openbao are affected by CVE-2026-55775? github.com/openbao/openbao (go) versions < 0.0.0-20260617103935-d3c1cc64b1ae is affected.
- Is there a fix for CVE-2026-55775? Yes. CVE-2026-55775 is fixed in 0.0.0-20260617103935-d3c1cc64b1ae. Upgrade to this version or later.
- Is CVE-2026-55775 exploitable, and should I be worried? Whether CVE-2026-55775 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-55775 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-55775? Upgrade
github.com/openbao/openbaoto 0.0.0-20260617103935-d3c1cc64b1ae or later.