CVE-2023-40023 is a medium-severity (CVSS 6.5) Information Exposure vulnerability in github.com/yaklang/yaklang. A fix is available for github.com/yaklang/yaklang — see the affected versions and patch details below.
Yaklang Plugin's Fuzztag Component Allows Unauthorized Local File Reading
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-40023.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-40023 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/yaklang/yaklangReal-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
The Yak Engine has been found to contain a local file inclusion (LFI) vulnerability. This vulnerability allows attackers to include files from the server's local file system through the web application. When exploited, this can lead to the unintended exposure of sensitive data, potential remote code execution, or other security breaches. Users utilizing versions of the Yak Engine prior to 1.2.4-sp1 are impacted.
Patches
The vulnerability has been addressed and patched. Users are advised to upgrade to Yak Engine version 1.2.4-sp1 immediately. The patch can be viewed and reviewed at this PR: https://github.com/yaklang/yaklang/pull/295，https://github.com/yaklang/yaklang/pull/296
Workarounds
Currently, the most effective solution is to upgrade to the patched version of Yak Engine (1.2.4-sp1). Users are also advised to avoid exposing vulnerable versions to untrusted input and to closely monitor any unexpected server behavior until they can upgrade.
References
For more details on the vulnerability and the corresponding patch, please visit the following link:
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/yaklang/yaklang | all versions | 1.2.4-sp2go get github.com/yaklang/yaklang@v1.2.4-sp2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/yaklang/yaklang, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/yaklang/yaklang to 1.2.4-sp2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-40023 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-40023 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-40023. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-40023 in your dependencies?
O3 Security finds CVE-2023-40023 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.