OpenBao has a Timing Side-Channel in the Userpass Auth Method

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

3.7 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS

• CVE-2025-54999: 0.21% estimated exploitation activity in the next 30 days; percentile 11.60 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact When using OpenBao's userpass auth method, user enumeration was possible due to timing difference between non-existent users and users with stored credentials. This is independent of whether the supplied credentials were valid for the given user. Patches OpenBao v2.3.2 will patch this issue. Workarounds Users may use another auth method or apply rate limiting quotas to limit the number of requests in a period of time: https://openbao.org/api-docs/system/rate-limit-quotas/ References This issue was disclosed to HashiCorp and is the OpenBao equivalent of the following tickets: - https://discuss.hashicorp.com/t/hcsec-2025-15-timing-side-channel-in-vault-s-userpass-auth-method/76034 - https://nvd.nist.gov/vuln/detail/CVE-2025-6011 Barring further information, this is also assumed to cover and remediate the following additional vulnerability: - https://discuss.hashicorp.com/t/hcsec-2025-21-vault-user-enumeration-in-userpass-auth-method/76095 -…

Published by the source

8 Aug 2025, 14:41 UTC

Last modified by the source

11 Aug 2025, 13:56 UTC

Source last checked

26 Oct 2026, 15:10 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-hh28-h22f-8357

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# Patch Next advisory brief: CVE-2025-54999

Advisory: OpenBao has a Timing Side-Channel in the Userpass Auth Method
IDs: CVE-2025-54999, GHSA-hh28-h22f-8357
Record: https://patchnext.com/advisories/cve-2025-54999 (revision 1, source checked 26 Oct 2026, 15:10 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 3.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/openbao/openbao 2.3.2, 0.0.0-20250806193356-4d9b5d3d6486. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/openbao/openbao: affected >= 0.1.0, < 2.3.2; < 0.0.0-20250806193356-4d9b5d3d6486; fixed in 0.0.0-20250806193356-4d9b5d3d6486, 2.3.2

## Suggested inspection (read-only)
- Go github.com/openbao/openbao: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/openbao/openbao.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-hh28-h22f-8357 (GitHub-reviewed advisory GHSA-hh28-h22f-8357 lists affected ranges: Go github.com/openbao/openbao >=0.1.0 =0 <0.0.0-20250806193356-4d9b5d3d6486)

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