CVE-2026-31866
Allocation of Resources Without Limits or Throttling in flagd
Description
flagd is a feature flag daemon with a Unix philosophy. Prior to 0.14.2, flagd 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. The 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). flagd 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. This vulnerability is fixed in 0.14.2.
INFO
Published Date :
March 11, 2026, 6:16 p.m.
Last Modified :
March 20, 2026, 4:21 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE |
Solution
- Update flagd to version 0.14.2 or later.
- Implement access controls for evaluation endpoints.
- Monitor memory usage of flagd instances.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-31866.
| URL | Resource |
|---|---|
| https://github.com/open-feature/flagd/commit/25c5fd7e80c26eb2c00b20317b2456fe6f927ea3 | Patch |
| https://github.com/open-feature/flagd/security/advisories/GHSA-rmrf-g9r3-73pm | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-31866 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-31866
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-31866 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-31866 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Mar. 20, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:openfeature:flagd:*:*:*:*:*:*:*:* versions up to (excluding) 0.14.2 Added Reference Type GitHub, Inc.: https://github.com/open-feature/flagd/commit/25c5fd7e80c26eb2c00b20317b2456fe6f927ea3 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/open-feature/flagd/security/advisories/GHSA-rmrf-g9r3-73pm Types: Vendor Advisory -
New CVE Received by [email protected]
Mar. 11, 2026
Action Type Old Value New Value Added Description flagd is a feature flag daemon with a Unix philosophy. Prior to 0.14.2, flagd 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. The 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). flagd 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. This vulnerability is fixed in 0.14.2. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-770 Added Reference https://github.com/open-feature/flagd/commit/25c5fd7e80c26eb2c00b20317b2456fe6f927ea3 Added Reference https://github.com/open-feature/flagd/security/advisories/GHSA-rmrf-g9r3-73pm