vulnerability / NVI-00016365 / Revision 1
OpenTofu has high CPU usage when using K8S remote state backend or when parsing specifically crafted TLS certificates from untrusted or compromised servers
GitHub lists this reviewed advisory for github.com/opentofu/opentofu, github.com/opentofu/opentofu. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
2.6 low
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
github.com/opentofu/opentofu
source listed>= 1.12.0-beta1, < 1.12.2
### Impact Unauthenticated denial of service. ### Summary When OpenTofu performs requests against an untrusted (or compromised) third-party server or connects to an attacker-controlled server, the initial connection negotiation can produce high CPU usage, leading to possible denial of service. These vulnerabilities **do not** permit arbitrary code execution or allow disclosure of confidential information. ### Details OpenTofu relies on third-party implementations of TLS certificate verification and HTTP request execution from the standard library of the Go programming language. The Go project has recently published the following advisories for those implementations which indirectly affect OpenTofu's behavior: - CVE-2026-42504: Quadratic complexity in WordDecoder.DecodeHeader in mime - CVE-2026-27145: Inefficient candidate hostname parsing in crypto/x509 CVE-2026-42504 affects OpenTofu's K8S remote state implementation. The operator of a configuration that uses such a backend needs to double-check the trustworthiness of the server used for this purpose. In situations where
github.com/opentofu/opentofu
source listed< 1.11.9
### Impact Unauthenticated denial of service. ### Summary When OpenTofu performs requests against an untrusted (or compromised) third-party server or connects to an attacker-controlled server, the initial connection negotiation can produce high CPU usage, leading to possible denial of service. These vulnerabilities **do not** permit arbitrary code execution or allow disclosure of confidential information. ### Details OpenTofu relies on third-party implementations of TLS certificate verification and HTTP request execution from the standard library of the Go programming language. The Go project has recently published the following advisories for those implementations which indirectly affect OpenTofu's behavior: - CVE-2026-42504: Quadratic complexity in WordDecoder.DecodeHeader in mime - CVE-2026-27145: Inefficient candidate hostname parsing in crypto/x509 CVE-2026-42504 affects OpenTofu's K8S remote state implementation. The operator of a configuration that uses such a backend needs to double-check the trustworthiness of the server used for this purpose. In situations where
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-22w5-2fxg-vrwx ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.