Skip to content
Fencer Intel
high —

GHSA-4c5f-9mj4-m247 json

flagd: Multiple Go Runtime CVEs Impact Security and Availability

published 10mo ago modified 8mo ago also GO-2026-4279

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
—
no score, EPSS covers CVEs only
public exploits
0
none known

Summary

### Summary 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. |

Patch / fix

  • go 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

Is GHSA-4c5f-9mj4-m247 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Affected packages

ecosystem package affected fixed in
go github.com/open-feature/flagd/core
<0.13.1
0.13.1
go github.com/open-feature/flagd/flagd-proxy
<0.8.2
0.8.2
go github.com/open-feature/flagd/flagd
<0.13.1
0.13.1

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-407 Inefficient Algorithmic Complexity
  • CWE-444 Inconsistent Interpretation of HTTP Requests
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.