GHSA-22w5-2fxg-vrwx
LOWGHSA-22w5-2fxg-vrwx is a low-severity (CVSS 2.6) remote code execution vulnerability in github.com/opentofu/opentofu. O3 Security confirms whether GHSA-22w5-2fxg-vrwx is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
OpenTofu has high CPU usage when using K8S remote state backend or when parsing specifically crafted TLS certificates from untrusted or compromised servers
Real-World Exposure
github.com/opentofu/opentofu🐹github.com/opentofu/opentofuReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
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 the server is untrusted or compromised, an attacker could configure it to respond with an intentionally crafted HTTP response designed to target this specific vulnerability in the Go standard library, potentially leading to high CPU usage.
CVE-2026-27145 has a similar outcome: if an untrusted or compromised third-party server is used, an attacker could craft a specific TLS certificate that targets this vulnerability in the Go standard library, which could also lead to high CPU usage.
Typical use of OpenTofu already requires caution in selection of third-party dependencies.
Patches
OpenTofu v1.11.9 and v1.12.2 address these vulnerabilities by upgrading to the Go versions that fix them (v1.25.11 and v1.26.3).
The OpenTofu v1.10 series is also impacted by these vulnerabilities. However, that series is built with a version of Go for which no upstream fix is available. Adopting Go 1.25.11 for that series would effectively end support for certain versions of macOS and Linux, and the OpenTofu Project has determined that the impact of these vulnerabilities is not high enough to justify that disruption in a patch release. For those using OpenTofu v1.10 releases, we recommend planning an upgrade to OpenTofu v1.11.9 in the near future.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/opentofu/opentofu | ≥ 1.12.0-beta1&&< 1.12.2 | 1.12.2 |
| 🐹Go | github.com/opentofu/opentofu | all versions | 1.11.9 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/opentofu/opentofu. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/opentofu/opentofu to 1.12.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-22w5-2fxg-vrwx is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-22w5-2fxg-vrwx is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-22w5-2fxg-vrwx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-22w5-2fxg-vrwx in your dependencies?
O3 detects GHSA-22w5-2fxg-vrwx across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.