---
id: "CVE-2026-47738"
page: "https://infrastack.ai/live/CVE-2026-47738"
kind: "vulnerability"
aliases: ["CVE-2026-47738"]
title: "liboqs: calling derandomized encapsulation on some NTRU KEMs can crash the process"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["c", "liboqs", "package", "post-quantum"]
not_affected_if: ["no-derandomized-encapsulation", "no-ntru-kem"]
published_at: "2026-11-06T22:17:51+00:00"
first_seen_at: "2026-11-06T22:44:32+00:00"
updated_at: "2026-11-06T22:44:51+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-47738", "first_seen_at": "2026-11-06T22:44:32+00:00"}]
exploit_sources: []
---

# liboqs: calling derandomized encapsulation on some NTRU KEMs can crash the process

Link for people: https://infrastack.ai/live/CVE-2026-47738 (this .md is for agents)

liboqs is a C post-quantum cryptography library. Before 0.16.0, calling OQS_KEM_encaps_derand on six NTRU KEMs dereferences an uninitialized function pointer, which an attacker can use to crash the calling process.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the liboqs version your application links against, for example `liboqs` in your package manager or `OQS_VERSION_TEXT` in `oqs/oqs.h`.
- Search your code for calls to `OQS_KEM_encaps_derand` and for instantiation of `OQS_KEM_ntru_hps2048509`, `OQS_KEM_ntru_hps2048677`, `OQS_KEM_ntru_hps4096821`, `OQS_KEM_ntru_hps40961229`, `OQS_KEM_ntru_hrss701` or `OQS_KEM_ntru_hrss1373`.

## Fix

- liboqs: `0.16.0`

## Timeline

- 2026-11-06T22:44:32+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-47738

## Documents

- [advisory] Vendor advisory: github.com https://github.com/open-quantum-safe/liboqs/security/advisories/GHSA-jr5q-r9qx-v738
- [fix] Patch: github.com https://github.com/open-quantum-safe/liboqs/commit/80ceff0207658eba98bae8eb22ca3aa2a364f40b
- [fix] Release notes: github.com https://github.com/open-quantum-safe/liboqs/releases/tag/0.16.0

## From the sources

liboqs is a C-language cryptographic library that provides implementations of post-quantum cryptography algorithms. Prior to 0.16.0, OQS_KEM_encaps_derand can dereference an uninitialized encaps_derand function pointer when called on NTRU-HPS-2048-509, NTRU-HPS-2048-677, NTRU-HPS-4096-821, NTRU-HPS-4096-1229, NTRU-HRSS-701, or NTRU-HRSS-1373. The affected NTRU constructors omit the OQS_KEM.encaps_derand member because those schemes do not support derandomized encapsulation, OQS_KEM objects are allocated without zero initialization, and the wrapper in src/kem/kem.c checks only that the OQS_KEM pointer is non-null before calling through the residual heap value. An application is affected only if it instantiates one of those six NTRU KEMs and invokes OQS_KEM_encaps_derand on it. The supported impact is a calling-process crash and denial of service. This issue is fixed in version 0.16.0.

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