GitHub Advisoryadvisory · Go

GHSA-4c5f-9mj4-m247 flagd: Multiple Go Runtime CVEs Impact Security and Availability

HIGH Published 2026-01-05 Modified 2026-01-05 Official page ↗
Ecosystem
Go
Packages
github.com/open-feature/flagd/core, github.com/open-feature/flagd/flagd-proxy, github.com/open-feature/flagd/flagd
Severity
High
Weaknesses
CWE-20, CWE-362, CWE-400, CWE-407, CWE-444, CWE-770
Reviewed
2026-01-05

Affected packages

• Go github.com/open-feature/flagd/core: < 0.13.1 → fixed in 0.13.1 • Go github.com/open-feature/flagd/flagd-proxy: < 0.8.2 → fixed in 0.8.2 • Go github.com/open-feature/flagd/flagd: < 0.13.1 → fixed in 0.13.1

Description

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. |

Related

Weakness · CWE (6)

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

References