---
id: CVE-2026-74888
title: openssl_encrypt before 1.4.0 Non-Standard PBKDF2 Key Derivation
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: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cvssSource: cna
cwe:
  - CWE-327
vendor: jahlives
product: openssl_encrypt
affected:
  - openssl_encrypt < 1.4.0
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-08-17T12:48:14.297282Z'
published: '2026-08-17'
updated: '2026-10-01'
sourceUpdated: '2026-10-01T15:20:59.221Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-74888'
references:
  - url: >-
      https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-743f-89fg-x288
    label: GitHub Security Advisory (GHSA-743f-89fg-x288)
  - url: >-
      https://www.vulncheck.com/advisories/openssl-encrypt-before-non-standard-pbkdf2-key-derivation
    label: >-
      VulnCheck Advisory: openssl_encrypt before 1.4.0 Non-Standard PBKDF2 Key
      Derivation
tags:
  - cve.org
  - osv
  - pip
epss: 0.00272
epssPercentile: 0.19402
aliases:
  - PYSEC-2026-3764
  - GHSA-743f-89fg-x288
ecosystem: pip
patched:
  - openssl-encrypt 1.4.0
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

- `openssl_encrypt < 1.4.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-74888)

Affected packages:

- `openssl-encrypt < 1.4.0`

Patched in:

- `openssl-encrypt 1.4.0`

Source: https://osv.dev/vulnerability/PYSEC-2026-3764