What is GHSA-4C5F-9MJ4-M247?

GHSA-4C5F-9MJ4-M247 is a high-severity improper input validation vulnerability in github.com/open-feature/flagd/core (go), affecting versions < 0.13.1. It is fixed in 0.13.1, 0.8.2. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.

Which packages are affected by GHSA-4C5F-9MJ4-M247?

github.com/open-feature/flagd/core (go) versions < 0.13.1; github.com/open-feature/flagd/flagd-proxy (go) versions < 0.8.2; github.com/open-feature/flagd/flagd (go) versions < 0.13.1.

Is there a fix for GHSA-4C5F-9MJ4-M247?

Yes. GHSA-4C5F-9MJ4-M247 is fixed in 0.13.1, 0.8.2. Upgrade to this version or later.

Is GHSA-4C5F-9MJ4-M247 exploitable, and should I be worried?

Whether GHSA-4C5F-9MJ4-M247 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.

What actually determines whether GHSA-4C5F-9MJ4-M247 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.

GHSA-4C5F-9MJ4-M247

Q: Which packages are affected by GHSA-4C5F-9MJ4-M247?

github.com/open-feature/flagd/core (go) versions < 0.13.1; github.com/open-feature/flagd/flagd-proxy (go) versions < 0.8.2; github.com/open-feature/flagd/flagd (go) versions < 0.13.1.

Q: Is there a fix for GHSA-4C5F-9MJ4-M247?

Yes. GHSA-4C5F-9MJ4-M247 is fixed in 0.13.1, 0.8.2. Upgrade to this version or later.

Q: Is GHSA-4C5F-9MJ4-M247 exploitable, and should I be worried?

Whether GHSA-4C5F-9MJ4-M247 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.

Q: What actually determines whether GHSA-4C5F-9MJ4-M247 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.

Q: How do I fix GHSA-4C5F-9MJ4-M247?

Upgrade: github.com/open-feature/flagd/core to 0.13.1 or later, github.com/open-feature/flagd/flagd-proxy to 0.8.2 or later, github.com/open-feature/flagd/flagd to 0.13.1 or later.

Summary

flagd: Multiple Go Runtime CVEs Impact Security and Availability

In 2025, several vulnerabilities in the Go Standard Library were disclosed, impacting Go-based applications like flagd (the evaluation engine for OpenFeature). These CVEs primarily focus on Denial of Service (DoS) through resource exhaustion and Race Conditions in database handling.

CVE ID	Impacted Package	Severity	Description & Impact on flagd
CVE-2025-47907	database/sql	7.0 (High)	Race Condition: Canceling a query during a Scan call can return data from the wrong query. Critical if flagd uses SQL-based sync providers (e.g., Postgres), potentially leading to incorrect flag configurations.
CVE-2025-61725	net/mail	7.5 (High)	DoS: Inefficient complexity in ParseAddress. Attackers can provide crafted email strings with large domain literals to exhaust CPU if flagd parses email-formatted metadata.
CVE-2025-61723	encoding/pem	7.5 (High)	DoS: Quadratic complexity when parsing invalid PEM inputs. Relevant if flagd loads TLS certificates or keys via PEM files from untrusted sources.
CVE-2025-61729	crypto/x509	7.5 (High)	Resource Exhaustion: HostnameError.Error() lacks string concatenation limits. A malicious TLS certificate with thousands of hostnames could crash flagd during connection handshakes.
CVE-2025-58188	net/http	Medium	Request Smuggling: Improper header handling in HTTP/1.1. Could allow attackers to bypass security filters positioned in front of flagd sync or evaluation APIs.
CVE-2025-58187	archive/zip	Medium	DoS: Improper validation of malformed ZIP archives. Impacts flagd if configured to fetch and unpack zipped configuration bundles from remote providers.

Impact

The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.

Affected versions

github.com/open-feature/flagd/core (< 0.13.1) github.com/open-feature/flagd/flagd-proxy (< 0.8.2) github.com/open-feature/flagd/flagd (< 0.13.1)

Security releases

github.com/open-feature/flagd/core → 0.13.1 (go) github.com/open-feature/flagd/flagd-proxy → 0.8.2 (go) github.com/open-feature/flagd/flagd → 0.13.1 (go)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

Upgrade the following packages to resolve this vulnerability:

github.com/open-feature/flagd/core to 0.13.1 or later; github.com/open-feature/flagd/flagd-proxy to 0.8.2 or later; github.com/open-feature/flagd/flagd to 0.13.1 or later

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

What is GHSA-4C5F-9MJ4-M247? GHSA-4C5F-9MJ4-M247 is a high-severity improper input validation vulnerability in github.com/open-feature/flagd/core (go), affecting versions < 0.13.1. It is fixed in 0.13.1, 0.8.2. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
Which packages are affected by GHSA-4C5F-9MJ4-M247?
- github.com/open-feature/flagd/core (go) (versions < 0.13.1)
- github.com/open-feature/flagd/flagd-proxy (go) (versions < 0.8.2)
- github.com/open-feature/flagd/flagd (go) (versions < 0.13.1)
Is there a fix for GHSA-4C5F-9MJ4-M247? Yes. GHSA-4C5F-9MJ4-M247 is fixed in 0.13.1, 0.8.2. Upgrade to this version or later.
Is GHSA-4C5F-9MJ4-M247 exploitable, and should I be worried? Whether GHSA-4C5F-9MJ4-M247 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
What actually determines whether GHSA-4C5F-9MJ4-M247 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.
How do I fix GHSA-4C5F-9MJ4-M247?
- Upgrade github.com/open-feature/flagd/core to 0.13.1 or later
- Upgrade github.com/open-feature/flagd/flagd-proxy to 0.8.2 or later
- Upgrade github.com/open-feature/flagd/flagd to 0.13.1 or later