# CVE-2026-46405: OpenBao's Kerberos Auth Method Accumulates Unaccessible Tokens

> Unauthenticated requests to OpenBao's Kerberos auth method create hidden tokens, potentially exhausting resources and causing denial of service.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Aug 2026
- **Updated:** 13 Aug 2026
- **Also known as:** BIT-openbao-2026-46405, GHSA-7j6w-vvw2-5f9c, GO-2026-5225

## What is CVE-2026-46405?

CVE-2026-46405 is a medium-severity denial of service vulnerability in openbao, published on 7 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.4, 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`. This is fixed in OpenBao v2.5.4. As a workaround, 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.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-46405?

4 open source packages ship an affected version, including github.com/openbao/openbao and openbao.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/openbao/openbao` | Go | All versions | None |
| `github.com/openbao/openbao` | Go | All versions | 2.5.4 |
| `github.com/openbao/openbao` | Go | All versions | 2.5.4 |
| `openbao` | Bitnami | All versions | 2.5.4 |

## How do I fix CVE-2026-46405?

Upgrade github.com/openbao/openbao to 2.5.4 or later.

## Is CVE-2026-46405 being exploited?

There is no known exploitation of CVE-2026-46405 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46405 and fix it if it is affected.

What it is: CVE-2026-46405 is a medium-severity denial of service vulnerability in openbao, published on 7 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-46405 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/openbao/openbao (Go): affected all versions; no fix listed
- github.com/openbao/openbao (Go): affected all versions; fixed in 2.5.4
- github.com/openbao/openbao (Go): affected all versions; fixed in 2.5.4
- openbao (Bitnami): affected all versions; fixed in 2.5.4

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-46405/ (Markdown: https://insights.sbomify.com/CVE-2026-46405/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46405
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46405
- OSV: https://osv.dev/vulnerability/CVE-2026-46405

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46405/
Summaries are generated and may contain mistakes; the official description above is the record.