CVE-2025-59823: Gardener provider extensions vulnerable to code injection when Terraform is used for infrastructure provisioning

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.5%, percentile 44: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 44% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Only applies if your dependency tree includes github.com/gardener/gardener-extension-provider-aws (Go) < 1.64.0, fixed in 1.64.0; github.com/gardener/gardener-extension-provider-gcp (Go) < 1.46.0, fixed in 1.46.0; github.com/gardener/gardener-extension-provider-azure (Go) < 1.55.0, fixed in 1.55.0; github.com/gardener/gardener-extension-provider-openstack (Go) < 1.49.0, fixed in 1.49.0. Check your lockfile, including transitive dependencies.

What it is

Project Gardener implements the automated management and operation of Kubernetes clusters as a service. Code injection may be possible in Gardener Extensions for AWS providers prior to version 1.64.0, Azure providers prior to version 1.55.0, OpenStack providers prior to version 1.49.0, and GCP providers prior to version 1.46.0. This vulnerability could allow a user with administrative privileges for a Gardener project to obtain control over the seed cluster where the shoot cluster is managed. This affects all Gardener installations where Terraformer is used/can be enabled for infrastructure provisioning with any of the affected components. This issue has been patched in Gardener Extensions for AWS providers version 1.64.0, Azure providers version 1.55.0, OpenStack providers version 1.49.0, and GCP providers version 1.46.0.

From the GitHub advisory

Impact

A security vulnerability was discovered in Gardener when Terraformer is used for infrastructure provisioning. This vulnerability could allow a user with administrative privileges for a Gardener project to obtain control over the seed cluster where the shoot cluster is managed.

This CVE affects all Gardener installations where Terraformer is used/can be enabled for infrastructure provisioning with any of the affected components mentioned below.

Affected Components • gardener-extension-provider-gcp • gardener-extension-provider-azure • gardener-extension-provider-openstack • gardener-extension-provider-aws

Affected Versions • gardener-extension-provider-gcp

Weakness type: CWE-94, CWE-20.

Product: github.com/gardener/gardener-extension-provider-aws (Go) · Assigned by: GitHub_M · Published: 2025-09-25

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.53% probability of exploitation activity in the next 30 days; percentile 44.

Timeline

• 2025-09-25 — CVE record published by GitHub_M
• 2025-09-25 — GitHub-reviewed advisory GHSA-227x-7mh8-3cf6 published (critical)
• 2025-09-29 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-227x-7mh8-3cf6 github.com
2. CVE.org record CVE-2025-59823 cve.org
3. NVD entry CVE-2025-59823 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com
5. github.com github.com
6. github.com github.com
7. github.com github.com
8. github.com github.com
9. github.com github.com
10. pkg.go.dev pkg.go.dev

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