---
id: CVE-2026-74888
aliases:
  - PYSEC-2026-3764
  - GHSA-743f-89fg-x288
title: >-
  openssl_encrypt versions before 1.4.0 use a non-standard PBKDF2 key derivation
  construction with iterations=1 per call in an outer loop, …
summary: >-
  openssl_encrypt versions before 1.4.0 use a non-standard PBKDF2 key derivation
  construction with iterations=1 per call in an outer loop, creating a KDF whose
  security properties have not been formally analyzed. Attackers can exploit
  this…
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-2026-3764'
references:
  - url: >-
      https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-743f-89fg-x288
  - url: >-
      https://www.vulncheck.com/advisories/openssl-encrypt-before-non-standard-pbkdf2-key-derivation
tags:
  - osv
  - pip
epss: 0.00272
epssPercentile: 0.17439
ingestedAt: '2026-09-02T19:31:25.578Z'
---

## Overview

openssl_encrypt versions before 1.4.0 use a non-standard PBKDF2 key derivation construction with iterations=1 per call in an outer loop, creating a KDF whose security properties have not been formally analyzed. Attackers can exploit this weakened key derivation to more efficiently crack passwords protecting legacy encrypted files compared to standard PBKDF2 implementations.

## Affected packages

- `openssl-encrypt < 1.4.0`

## Remediation

Upgrade to a patched release:

- `openssl-encrypt 1.4.0`