Vulnerability · Published Aug 17, 2026 · Assigned by VulnCheck

CVE-2026-74888openssl_encrypt before 1.4.0 Non-Standard PBKDF2 Key Derivation

High 7.5

In plain English

A high-severity broken cryptography in openssl_encrypt from jahlives. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.3%top 80.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	openssl-encrypt	1.4.0	PYSEC-2026-3764

Affected products (as reported)

Vendor	Product	Versions
jahlives	openssl_encrypt	0 – before 1.4.0

Weakness: CWE-327 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

GitHub Security Advisory (GHSA-743f-89fg-x288) vendor-advisory
VulnCheck Advisory: openssl_encrypt before 1.4.0 Non-Standard PBKDF2 Key Derivation third-party-advisory