CVE-2026-31866
CWE-770Published: March 11, 2026· Updated: Mar 12, 2026
Official 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.
Technical Analysis
CVE-2026-31866 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
All References (2)
Quick Facts
Related CVEs (CWE-770)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-31866 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts