Eight intermediate certificate authorities operated by eMudhra have been found to have trivially-recoverable private keys, requiring updates to CA root stores to distrust the weak keys and prevent a potential man-in-the-middle attack.
Customers must update the Oxide CLI, Rust SDK, Terraform provider, Packer plugin, Kubernetes integrations, OpenTelemetry Collector components, Vault plugins, and their operating system CA root store to fully distrust the affected certificates.
Customers should update the Oxide Cloud Computer to system release 23.2 to prevent man-in-the-middle attacks when sending alert webhooks and fetching SAML identity provider metadata.
| Revision | Date (YYYYMMDD) | Changes |
|---|---|---|
1.0 | 20261105 | Initial Release |
Impacted Products
Oxide Cloud Computer system releases 23.1 and older.
Oxide Rust SDK and CLI versions v0.19.0+2026091500.0.0 or v0.18.0+2026073100.0.0 and older.
Oxide Terraform provider version v0.23.1 and older.
Oxide Packer plugin version v0.9.0 and older.
Oxide OpenTelemetry Collector components version v0.6.0 and older.
Oxide Vault auth and secrets plugins version v0.1.0 and older.
Kubernetes integrations:
Oxide infrastructure provider for Cluster API (CAPOx) version v0.2.3 and older.
Oxide Cloud Controller Manager (CCM) version v0.8.0 and older.
Oxide Omni infrastructure provider version v0.5.0 and older.
Oxide Rancher node driver version v0.13.0 and older.
Oxide Karpenter plugin version v0.2.5 and older.
Impact
A man-in-the-middle attacker can impersonate a remote system that the Oxide Cloud Computer makes requests to in the following circumstances:
An alert is sent to a webhook receiver configured with an
https:/URL./ During SAML identity provider creation, an
https:/URL is used as the metadata source./
A man-in-the-middle attacker can impersonate the Oxide Cloud Computer using a server certificate signed by one of the weak intermediate CAs if it is still trusted by the client.
Action Required
Oxide recommends that customers update to system release 23.2; however, if no HTTPS webhook receivers are configured and the mitigation below is acceptable, it is reasonable to wait until the next scheduled maintenance window or the next Oxide system release.
Client recommendations:
Ensure that your operating system’s CA root stores are updated.
Update the Oxide Rust SDK and CLI to:
version v0.19.1+2026091500.0.0, for use with system release 23 and later.
version v0.18.1+2026073100.0.0, for use with system release 22 and later.
Update the Oxide Terraform provider to version v0.23.2.
Update the Oxide Packer plugin to version v0.9.1.
Update the Oxide OpenTelemetry Collector components to version v0.7.0.
Update the Oxide Vault auth and secrets plugins to version v0.2.0.
Update Oxide Kubernetes integrations:
Oxide infrastructure provider for Cluster API (CAPOx) to version v0.3.0.
Oxide Cloud Controller Manager (CCM) to version v0.8.1.
Oxide Omni infrastructure provider to version v0.6.0.
Oxide Rancher node driver version to v0.13.1.
Oxide Karpenter plugin to version v0.2.6.
Mitigations
When creating SAML identity providers, provide the metadata in XML format directly instead of providing a metadata URL.
There are no mitigations for impacted client products.
Technical Background
TLS relies on public key infrastructure to establish trust on the Internet. The main four browsers, and all major operating systems maintain root stores of ultimately-trusted root certificate authorities, and the root CAs sign intermediate CAs that sign end-user certificates. For inclusion in the root stores, CAs must demonstrate a sufficient set of controls to ensure that only owners can obtain trusted certificates for their infrastructure.
On 2026-10-20 the Web Public Key Infrastructure (WebPKI) root store operators advised that the private keys of eight eMudhra intermediate CA certificates are trivially recoverable. Anyone can recover the private key to these intermediate CAs, sign end-user certificates, and use the valid certificates to decrypt traffic. While browser vendors are able to immediately distrust certificates out-of-band, TLS clients outside of browsers require operating system updates or independent updates to their root stores.
Oxide system release 23.2 contains OS images with an updated Mozilla CA root store, as well as fixes to the rustls-webpki and webpki-roots Rust crates to ensure Nexus distrusts the affected intermediate certificates. The only component of the Oxide control plane that is a TLS client is Nexus, which can make HTTPS requests to send alerts to webhook receivers and fetch SAML identity provider metadata documents.
The Oxide Rust SDK and CLI include the CA root store distributed by the webpki-roots Rust crate, and must be updated to completely distrust the affected intermediate certificates.
The remaining affected clients use the Oxide Go SDK. Go applications need to be rebuilt using Go 1.26.10 or 1.27.3 to completely distrust the affected intermediate certificates.