CVE-2026-31866: Github.com/open feature/flagd/flagd Remote Code Execution Vulnerability
HIGHCVE-2026-31866 is a HIGH (CVSS 7.5) remote code execution vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Github.com/open feature/flagd/flagd libraries in the Go ecosystem. The issue involves flagd vulnerable to allocation of resources without limits or throttling. Remediation is available by upgrading affected packages to version 0.14.2.
CVE-2026-31866 at a Glance
Security Impact
CVSS: 7.5
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
How to Fix CVE-2026-31866
To remediate this vulnerability, upgrade all affected Github.com/open feature/flagd/flagd dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/open-feature/flagd/flagd to 0.14.2Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/open-feature/flagd/flagdHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-31866, inspect your project dependencies for Github.com/open feature/flagd/flagd:
inspect dependencies for github.com/open-feature/flagd/flagdAnalyze the terminal output to locate any version of Github.com/open feature/flagd/flagd in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.14.2), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. In Github.com/open feature/flagd/flagd, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-31866 Affected Github.com/open feature/flagd/flagd Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/open-feature/flagd/flagd
|
Go |
< 0.14.2
|
0.14.2
|
References
Frequently Asked Questions
What is CVE-2026-31866?
Which Github.com/open feature/flagd/flagd versions are affected?
What version fixes CVE-2026-31866?
Is github.com/open-feature/flagd/flagd affected?
What is the CVSS score of CVE-2026-31866?
What CWE is associated with CVE-2026-31866?
How can I check Go dependencies for CVE-2026-31866?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-rmrf-g9r3-73pm",
"modified" : "2026-03-11T20:57:35Z",
"published" : "2026-03-11T00:33:30Z",
"aliases" : [ "CVE-2026-31866" ],
"summary" : "flagd Vulnerable to Allocation of Resources Without Limits or Throttling",
"details" : "## Details\n\nflagd exposes OFREP (`/ofrep/v1/evaluate/...`) and gRPC (`evaluation.v1`, `evaluation.v2`) endpoints for feature flag evaluation. These endpoints are designed to be publicly accessible by client applications.\n\nThe evaluation context included in request payloads is read into memory without any size restriction. An attacker can send a single HTTP request with an arbitrarily large body, causing flagd to allocate a corresponding amount of memory. This leads to immediate memory exhaustion and process termination (e.g., OOMKill in Kubernetes environments).\n\nflagd does not natively enforce authentication on its evaluation endpoints. While operators may deploy flagd behind an authenticating reverse proxy or similar infrastructure, the endpoints themselves impose no access control by default.\n\n## Impact\n\n- **Denial of Service:** A single crafted request can crash the flagd process.\n- **Service Disruption:** All applications relying on the affected flagd instance for feature flag evaluation will lose access to flag evaluations until the process restarts.\n- **Repeated Exploitation:** An attacker can continuously send oversized requests to prevent recovery.\n\n## Affected Endpoints\n\n- `/ofrep/v1/evaluate/flags/{flagKey}` (OFREP single flag evaluation)\n- `/ofrep/v1/evaluate/flags` (OFREP bulk evaluation)\n- `flagd.evaluation.v1.Service/ResolveBoolean` (gRPC/Connect)\n- `flagd.evaluation.v1.Service/ResolveString` (gRPC/Connect)\n- `flagd.evaluation.v1.Service/ResolveFloat` (gRPC/Connect)\n- `flagd.evaluation.v1.Service/ResolveInt` (gRPC/Connect)\n- `flagd.evaluation.v1.Service/ResolveObject` (gRPC/Connect)\n- `flagd.evaluation.v1.Service/ResolveAll` (gRPC/Connect)\n- `flagd.evaluation.v2.Service/ResolveBoolean` (gRPC/Connect)\n- `flagd.evaluation.v2.Service/ResolveString` (gRPC/Connect)\n- `flagd.evaluation.v2.Service/ResolveFloat` (gRPC/Connect)\n- `flagd.evaluation.v2.Service/ResolveInt` (gRPC/Connect)\n- `flagd.evaluation.v2.Service/ResolveObject` (gRPC/Connect)",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/open-feature/flagd/flagd"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.14.2"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/open-feature/flagd/security/advisories/GHSA-rmrf-g9r3-73pm"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-31866"
}, {
"type" : "WEB",
"url" : "https://github.com/open-feature/flagd/commit/25c5fd7e80c26eb2c00b20317b2456fe6f927ea3"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/open-feature/flagd"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-770" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-03-11T00:33:30Z",
"nvd_published_at" : "2026-03-11T18:16:25Z"
}
}