Overview

The Vault 1.16.x upgrade guide contains information on deprecations, important or breaking changes, and remediation recommendations for anyone upgrading from Vault 1.15. Please read carefully.

Important changes

External plugin variables take precedence over system variables

Vault gives precedence to plugin environment variables over system environment variables when loading external plugins. The behavior for builtin plugins and plugins that do not specify additional environment variables is unaffected.

For example, if you register an external plugin with SOURCE=child in the env parameter but the main Vault process already has SOURCE=parent defined, the plugin process starts with SOURCE=child.

Refer to the plugin management page for more details on plugin environment variables.

How to opt out

To opt out of the precedence change, set the VAULT_PLUGIN_USE_LEGACY_ENV_LAYERING environment variable to true for the main Vault process:

$ export VAULT_PLUGIN_USE_LEGACY_ENV_LAYERING=true

Setting VAULT_PLUGIN_USE_LEGACY_ENV_LAYERING to true tells Vault to:

1. prioritize environment variables from the Vault server environment whenever the system detects a variable conflict.
2. report on plugin variable conflicts during the unseal process by printing warnings for plugins with conflicting environment variables or logging an informational entry when there are no conflicts.

For example, assume you set VAULT_PLUGIN_USE_LEGACY_ENV_LAYERING to true and have an environment variable SOURCE=parent.

If you register an external plugin called myplugin with SOURCE=child, the plugin process starts with SOURCE=parent and Vault reports a conflict for myplugin.

LDAP auth entity alias names no longer include upndomain

The userattr field on the LDAP auth config is now used as the entity alias. Prior to 1.16, the LDAP auth method would detect if upndomain was configured on the mount and then use <cn>@<upndomain> as the entity alias value.

The consequence of not configuring this correctly means users may not have the correct policies attached to their tokens when logging in.

How to opt out

To opt out of the entity alias change, update the userattr field on the config:

userattr="userprincipalname"

Refer to the LDAP auth method (API) page for more details on the configuration.

Secrets Sync now requires setting a one-time flag before use

To use the Secrets Sync feature, the feature must be activated with a new one-time operation called an activation-flag. The feature is gated until a Vault operator decides to trigger the flag. More information can be found in the secrets sync documentation.

Known issues and workarounds

JWT auth login requires bound audiences on the role

Affected versions

• 1.15.9
• 1.15.10
• 1.15.11
• 1.16.3
• 1.16.4
• 1.16.5

Issue

A behavior change was made in the jwt auth plugin to address CVE-2024-5798. Since the behavior change was a breaking change, we reverted the change in the versions 1.15.12 and 1.16.6 and later. However, the behavior change will go into effect in 1.17.

The new behavior requires that the bound_audiences parameter of "jwt" roles must be set and must match at least one of the JWT's associated aud claims if there are any. The aud claim can be a single string or a list of strings as per RFC 7519 Section 4.1.3.

Users may not be able to log into Vault if the JWT role is configured incorrectly. For additional details, refer to the JWT auth method (API) documentation.

See this issue for more details.

Workaround

Configure the bound_audiences parameter of "jwt" roles to match at least one of the JWT's associated aud claims. This configuratoin will be required for 1.17 and later.

Error configuring the JWT auth method

Affected versions

• 1.16.1

Issue

An error will occur when configuring the built-in jwt auth method. This will affect new mounts and updates to existing mounts. Existing mounts should not encounter an error if no modifications are made.

See this issue for more details.

This issue is addressed in Vault 1.16.2 and later.

Workaround

Do not attempt to update an existing mount's config. New mounts can run the plugin as an external plugin to avoid the error.

Error logging in with LDAP auth method when anonymous group search is enabled

Affected versions

• 1.16.0

Issue

Depending on their LDAP configuration, some customers may encounter an error when attempting to login with ldap auth method when anonymous group search is enabled. See this issue for more details.

This issue was resolved in 1.16.1.

Workaround

There is no workaround.

Error logging in with LDAP auth method

Affected versions

• 1.16.0

Issue

Depending on their LDAP configuration, some customers may encounter an error when attempting to login with ldap auth method. Active Directory users are affected by this bug. See this issue for more details.

This issue was resolved in 1.16.1.

Workaround

There is no workaround.

Existing clusters do not show the current Vault version in UI by default

Affected versions

• 1.16+

Issue

Previous versions of the Vault UI fetched version information from un-authenticated endpoints like sys/health and sys/seal-status. Since introducing the redact_version TCP listener parameter, version information may no longer be available under some configurations. As a result, the Vault UI now uses a new, authenticated endpoint (sys/internal/ui/version) to fetch version information.

By default, all new Vault servers created with v1.16+ include the following rule, in the automatically-generated policy:

# Allow a token to look up the Vault version. This path is not subject to
# redaction like the unauthenticated endpoints that provide the Vault version.
path "sys/internal/ui/version" {
    capabilities = ["read"]
}

However, the default policy for existing Vault servers does not update automatically during the upgrade. You must updated the policy manually in order for the Vault version to be displayed in the Vault UI.

No other functionality in the Vault UI is affected be this issue.

You can use the Vault CLI to update the default policy and allow the Vault IU to query the Vault server for version information:

$ vault policy read default | cat - <<< '
# Allow a token to look up the Vault version. This path is not subject to
# redaction like the unauthenticated endpoints that provide the Vault version.
path "sys/internal/ui/version" {
    capabilities = ["read"]
}
' > default-policy.hcl
$ vault policy write default ./default-policy.hcl

Default lease count quota enabled when upgrading from Vault versions before 1.9

Affected versions

• 1.16+

Issue

Vault began tracking version history as of version 1.9. As of version 1.16, new Vault installs automatically enable a lease count quota by consulting the version history. If the version history is empty on upgrade, Vault treats the upgrade as a new install and automatically enables a default lease count quota.

Before you upgrade Vault from a version prior to 1.9 to versions 1.16+, you should check the current number of unexpired leases via the vault.expire.num_leases metric.

If the number of unexpired leases is below the default lease count quota, value of 300000 no extra steps are required.

If the number of unexpired leases is greater than the default threshold of 300000, there is a two step workaround to safely upgrade without the default lease count quota:

1. Upgrade to any Vault version prior to 1.16 (between 1.9 and 1.15) to populate the version store.
2. Upgrade to Vault version 1.16+.

You can review, modify, and delete the global default quota at any point with the /sys/quotas/lease-count/default endpoint:

$ vault read sys/quotas/lease-count/default
$ vault delete sys/quotas/lease-count/default
$ vault write sys/quotas/lease-count/default max_leases=<# of max leases>

Refer to Protecting Vault with Resource Quotas for a step-by-step tutorial on quota tuning.

Refer to Lease Explosions for more information on lease management.

PKI OCSP GET requests can return HTTP redirect responses

If a base64 encoded OCSP request contains consecutive '/' characters, the GET request will return a 301 permanent redirect response. If the redirection is followed, the request will not decode as it will not be a properly base64 encoded request.

As a workaround, OCSP POST requests can be used which are unaffected.

Impacted versions

Affects all current versions of 1.12.x, 1.13.x, 1.14.x, 1.15.x, 1.16.x, 1.17.x.

Azure secrets engine role creation failing

Affected versions

• 1.16.0, 1.16.1, 1.16.2

Issue

Creating Azure Secrets engine roles by specifying the Azure App Registration Object ID as the application_object_id causes Vault to error out stating error loading Application: no application found. This was introduced by vault-plugin-secrets-azure v0.17.0, which incorrectly queries for an application by client_id and not application_object_id.

Workaround

Users can pass a client_id instead of an application_object_id into the application_object_id parameter. However, after upgrading to a version with a fix (1.16.3+), the user will need to remember to switch back to the application_object_id.

Performance Standbys revert to Standby mode on unseal

Affected versions

• 1.14.12
• 1.15.8
• 1.16.2

Issue

If you previously set a value for retention_months via the sys/internal/counters/config endpoint, upgrading to Vault Enterprise versions 1.14.12, 1.15.8, and 1.16.2 will cause Performance Standby nodes to revert to Standby mode.

Adding nodes with Vault Enterprise versions 1.14.12, 1.15.8, or 1.16.2 to a cluster with an older versioned leader will see any previously set retention_months value and attempt to write the new minimum value of 48. The storage write will result in a read-only error:

[ERROR] core: performance standby post-unseal setup failed: error="cannot write to readonly storage"

You can verify the status of your nodes by checking the /sys/health endpoint.

Deployments that rely on scaling across Performance Standbys will now forward all requests to the active node, increasing the utilization of the active node.

A fix for the read-only storage error has been prioritized and escalated. The fix will be in releases 1.14.13, 1.15.9 and 1.16.3.

Workaround

Once the leader of the cluster has been updgraded to version 1.14.12, 1.15.8, or 1.16.2, the workaround is to update the retention_months value on the active node via the sys/internal/counters/config endpoint:

$ vault write sys/internal/counters/config retention_months=48

This storage entry will be written to all nodes in the cluster, allowing them to immediately unseal as Performance Standbys.

After the new retention_months value is written to storage on the active node, adding new nodes to the cluster will not cause the read-only error.

Sending SIGHUP to vault standby node causes panic

Affected versions

• 1.13.4+
• 1.14.0+
• 1.15.0+
• 1.16.0+

Issue

Sending a SIGHUP to a vault standby node running an enterprise build can cause a panic if there is a change to the license, or reporting configuration. Active and performance standby nodes will perform fine. It is recommended that operators stop and restart vault nodes individually if configuration changes are required.

Workaround

Instead of issuing a SIGHUP, users should stop individual vault nodes, update the configuration or license and then restart the node.

New nodes added by autopilot upgrades provisioned with the wrong version

Affected versions

• 1.15.3 - 1.15.9
• 1.16.1 - 1.16.3

Issue

If autopilot_upgrade_version is not explicitly set in the Vault configuration file in the storage section, new non-active nodes will retain their original Vault version as opposed to the new version.

Workaround

Set the desired version in the configuration file as autopilot_upgrade_version=<version string>. This will allow all nodes to receive the proper version to upgrade to.

Secrets Sync cannot be activated from chroot namespace

Affected versions

• 1.16.0+

Issue

Secrets Sync cannot be activated from the chroot namespace. The Secrets Sync feature now requires a new activation-flag to be enabled before it can be used. Writing to any sys/activation-flags/ path currently requires root namespace access.

Workaround

Users can request a Vault operator to activate the feature from the root namespace if they lack the necessary access.

Potential DoS when using the deny_unauthorized proxy protocol behavior for a TCP listener

Affected versions

Community Edition (CE)

• 1.10.x - 1.15.x
• 1.17.1

Enterprise

• 1.10.x+ent - 1.15.11+ent
• 1.16.5+ent
• 1.17.1+ent

Issue

Vault TCP listeners configured with the deny_unauthorized proxy_protocol_behavior close if they receive a request from an untrusted upstream connection. As a result, Vault no longer responds to any request received through that listener.

Being able to force-close listeners with intentionally untrusted connections leaves the Vault API vulnerable to a denial-of-service (DoS) attacks, which could cause the API to become unavailable on that node.

The vulnerability is addressed in Vault 1.15.12+ent, 1.16.6+ent, 1.17.2, 1.17.2+ent and later.

Workaround

Do not configure a proxy_protocol_behavior with the deny_unauthorized value.