CVE-2026-81687: openssl_encrypt before 1.4.9 Denial of Service via KDF

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-27 · updated 2026-09-23
Weakness: CWE-400

Description

openssl_encrypt versions before 1.4.9 fail to enforce a time ceiling on key derivation function iteration counts specified in file metadata. Attackers can craft files with extremely high KDF iteration counts to consume CPU resources for unbounded periods before password verification occurs.

Affected products

jahlives openssl_encrypt: before 1.4.9 — fixed in 1.4.9

How to fix

Upgrade to a fixed version: jahlives openssl_encrypt 1.4.9. Check the vendor advisory for mitigations.

References

https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-rv6w-7hq9-pr74
https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-denial-of-service-via-kdf

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