Summary
OpenBao's Kerberos Auth Method Accumulates Unaccessible Tokens
Workarounds
Users may set a rate limit quota to limit the creation of these paths. As the path is unauthenticated, it isn't possible to deny access to it.
Reporter
This was discovered by an anonymous reporter.
Impact
In OpenBao's Kerberos auth method on the GET handler, or when an Authorization: Negotiate header is supplied, the response is includes a logical.Auth object in addition to an error message. This results in tokens being created with only the default policy, default TTL, and no entity information, which are hidden by the returned error message. No access to these tokens by the caller occurs and the authentication token is not ever made accessible outside of sys/raw. At most this could cause storage usage.
The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.
CVE-2026-46405 has a CVSS score of 5.3 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.5.4); upgrading removes the vulnerable code path.
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 is fixed in OpenBao v2.5.4.
Frequently Asked Questions
- What is CVE-2026-46405? CVE-2026-46405 is a medium-severity allocation of resources without limits or throttling vulnerability in github.com/openbao/openbao (go), affecting versions <= 2.5.3. It is fixed in 2.5.4. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.
- How severe is CVE-2026-46405? CVE-2026-46405 has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/openbao/openbao are affected by CVE-2026-46405? github.com/openbao/openbao (go) versions <= 2.5.3 is affected.
- Is there a fix for CVE-2026-46405? Yes. CVE-2026-46405 is fixed in 2.5.4. Upgrade to this version or later.
- Is CVE-2026-46405 exploitable, and should I be worried? Whether CVE-2026-46405 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-2026-46405 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-2026-46405? Upgrade
github.com/openbao/openbaoto 2.5.4 or later.