CVE-2026-27900

Workarounds and Mitigations

• Disable Terraform/provider debug logging or set it to WARN level or above
  • To disable the logging, you can unset TF_LOG_PROVIDER and TF_LOG environment variables
  • Or you can set them to WARN or ERROR levels to avoid sensitive information logged in INFO and DEBUG levels.
  • See Terraform docs for details: https://developer.hashicorp.com/terraform/internals/debugging
• Restrict access to existing and historical logs
• Purge/retention-trim logs that may contain sensitive values
• Rotate potentially exposed secrets/credentials, including:
  • Root passwords
  • Image share group tokens
  • TLS private keys/certificates used in NodeBalancer configs
  • StackScript content/secrets if embedded

Credits

This issue was reported to Terraform by Hasan Sheet via Akamai's HackerOne Bug Bounty program.

Resources

https://github.com/linode/terraform-provider-linode/releases/tag/v3.9.0
https://github.com/linode/terraform-provider-linode/pull/2269
https://github.com/linode/terraform-provider-linode/commit/43a925d826b999f0355de3dc7330c55f496824c0

The Terraform Provider for Linode versions prior to v3.9.0 logged sensitive information including some passwords, StackScript content, object storage data, and NodeBalancer TLS keys in debug logs without redaction.

Important: Provider debug logging is not enabled by default.
This issue is exposed when debug/provider logs are explicitly enabled (for example in local troubleshooting, CI/CD jobs, or centralized log collection). If enabled, sensitive values may be written to logs and then retained, shared, or exported beyond the original execution environment.

Specifically:

• Instance creation operations logged the full InstanceCreateOptions struct containing RootPass and StackScriptData
• Instance disk creation logged InstanceDiskCreateOptions containing RootPass and StackscriptData
• StackScript update operations logged the complete script content via StackscriptUpdateOptions.Script
• Image share group member creation logged tokens in ImageShareGroupAddMemberOptions.Token
• Object storage operations logged full PutObjectInput structures containing user data
• NodeBalancer config create and update operations logged NodeBalancerConfigCreateOptions and NodeBalancerConfigUpdateOptions containing the SSLKey (TLS private key)

An authenticated user with access to provider debug logs (through log aggregation systems, CI/CD pipelines, or debug output) would thus be able to extract these sensitive credentials.

CVE-2026-27900 has a CVSS score of 5.0 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.9.0); upgrading removes the vulnerable code path.

Kodem intelligence

Update to version v3.9.0 or later, which sanitizes debug logs by logging only non-sensitive metadata such as labels, regions, and resource IDs while redacting credentials, tokens, keys, scripts, and other sensitive content.

1. What is CVE-2026-27900? CVE-2026-27900 is a medium-severity security vulnerability in github.com/linode/terraform-provider-linode/v3 (go), affecting versions < 3.9.0. It is fixed in 3.9.0.
2. How severe is CVE-2026-27900? CVE-2026-27900 has a CVSS score of 5.0 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2026-27900?
   • github.com/linode/terraform-provider-linode/v3 (go) (versions < 3.9.0)
   • github.com/linode/terraform-provider-linode/v2 (go) (versions <= 2.41.2)
   • github.com/linode/terraform-provider-linode (go) (versions <= 1.30.0)
4. Is there a fix for CVE-2026-27900? Yes. CVE-2026-27900 is fixed in 3.9.0. Upgrade to this version or later.
5. Is CVE-2026-27900 exploitable, and should I be worried? Whether CVE-2026-27900 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-27900 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-27900? Upgrade github.com/linode/terraform-provider-linode/v3 to 3.9.0 or later.