How severe is GHSA-mjcp-gpgx-ggcg?

GHSA-mjcp-gpgx-ggcg has a CVSS score of 5.9/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-mjcp-gpgx-ggcg?

GHSA-mjcp-gpgx-ggcg affects the following packages: github.com/opentofu/opentofu (Go). Ecosystems affected: Go.

How do I fix GHSA-mjcp-gpgx-ggcg?

Update github.com/opentofu/opentofu to 1.10.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mjcp-gpgx-ggcg is resolved across your whole dependency graph.

How do I detect GHSA-mjcp-gpgx-ggcg in my Go dependencies?

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.

How do I mitigate GHSA-mjcp-gpgx-ggcg if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-mjcp-gpgx-ggcg?

O3 pinpoints whether GHSA-mjcp-gpgx-ggcg is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-mjcp-gpgx-ggcg actively exploited in the wild?

No public exploit code has been indexed for GHSA-mjcp-gpgx-ggcg yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-mjcp-gpgx-ggcg published, and has it been updated?

GHSA-mjcp-gpgx-ggcg was published on December 9, 2025 and was last updated on December 15, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

GHSA-mjcp-gpgx-ggcg

MEDIUM

OpenTofu incorrectly validates excluded subdomain constraint in conjunction with TLS certificates containing wildcard SANs

Also known asGO-2025-4224

Published

Dec 9, 2025

Updated

Dec 15, 2025

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Blast Radius

1 pkg affected

🐹github.com/opentofu/opentofu

Real-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

For example a constraint that excludes the subdomain test.example.com does not prevent a leaf certificate from claiming the SAN *.example.com.

Details

When acting as a TLS client, OpenTofu relies on the implementation of TLS certificate verification from the standard library of the Go programming language.

The Go project has recently published the following advisory for that which indirectly affects OpenTofu's behavior:

CVE-2025-61727: Improper application of excluded DNS name constraints when verifying wildcard names in crypto/x509

OpenTofu acts as a TLS client when calling a module or provider registry to request metadata, when downloading module or provider packages from "https" URLs, and when interacting with remote services for state storage and encryption. In these situations, OpenTofu could potentially accept as valid a certificate chain containing conflicting information about whether it is valid for the target hostname.

All certificates in the chain are still checked separately for validity, and so a successful attack requires an attacker-controlled server to produce a chain of valid-but-contradictory certificates and have access to the private keys associated with each one, and for the attacker to then arrange for OpenTofu to attempt to connect to the affected hostname.

Patches

OpenTofu v1.10.8 addresses these vulnerabilities by being built against Go 1.24.11, which contains an improved version of the upstream implementation.

The OpenTofu v1.9 and v1.8 series are also affected by these vulnerabilities. However, those series are built with a version of Go for which no upstream fix is available. Adopting Go 1.24.11 for those 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 the OpenTofu v1.9 or v1.8 releases we recommend planning to upgrade to OpenTofu v1.10.8 in the near future.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/opentofu/opentofu`	all versions	1.10.8

Detection & mitigation playbook

Open-source dependency

Detect
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 1.10.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mjcp-gpgx-ggcg 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-mjcp-gpgx-ggcg 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-mjcp-gpgx-ggcg. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

When OpenTofu is acting as a TLS client authenticating a certificate chain provided by a TLS server, an excluded subdomain constraint in a certificate chain does not restrict the usage of wildcard [SANs](https://en.wikipedia.org/wiki/Public_key_certificate#Subject_Alternative_Name_certificate) in the leaf certificate. For example a constraint that excludes the subdomain test.example.com does not prevent a leaf certificate from claiming the SAN *.example.com. ### Details When acting as a TLS client, OpenTofu relies on the implementation of TLS certificate verification from the standard libra

O3 Security · Impact-Aware SCA

Is GHSA-mjcp-gpgx-ggcg in your dependencies?

O3 detects GHSA-mjcp-gpgx-ggcg across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works