---
id: CVE-2026-74889
aliases:
  - PYSEC-2026-3765
  - GHSA-j9mh-57cc-665x
title: >-
  openssl_encrypt versions before 1.4.0 use HKDF with no salt and static info
  parameter in key normalization functions, reducing entropy ex…
summary: >-
  openssl_encrypt versions before 1.4.0 use HKDF with no salt and static info
  parameter in key normalization functions, reducing entropy extraction and
  determinism. Attackers can exploit predictable key derivation with identical
  inputs to …
severity: none
vendor: openssl-encrypt
product: openssl-encrypt
ecosystem: pip
affected:
  - openssl-encrypt < 1.4.0
patched:
  - openssl-encrypt 1.4.0
published: '2026-08-17'
updated: '2026-09-02'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/PYSEC-2026-3765'
references:
  - url: >-
      https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-j9mh-57cc-665x
  - url: >-
      https://www.vulncheck.com/advisories/openssl-encrypt-before-weak-key-derivation-via-hkdf
tags:
  - osv
  - pip
epss: 0.00348
epssPercentile: 0.25591
ingestedAt: '2026-09-02T19:31:25.619Z'
---

## Overview

openssl_encrypt versions before 1.4.0 use HKDF with no salt and static info parameter in key normalization functions, reducing entropy extraction and determinism. Attackers can exploit predictable key derivation with identical inputs to weaken cryptographic security against multi-target attacks.

## Affected packages

- `openssl-encrypt < 1.4.0`

## Remediation

Upgrade to a patched release:

- `openssl-encrypt 1.4.0`