# CVE-2026-81718: openssl_encrypt weak PBKDF2 parameters in keyfile encryption

Source: https://junglewise.ai/threats/cve-2026-81718-openssl-encrypt-weak-pbkdf2-parameters-in-keyfile-encryption  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-27. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-81718 · Severity: high · CVSS 7.5 · Published 2026-08-27

openssl_encrypt is a Python library for encrypting files and protecting cryptographic keys. Versions before 1.4.9 use insufficiently strong password-based key derivation (PBKDF2 with only 100,000 iterations) to protect stored private keys and verify passwords. An attacker who gains access to encrypted keyfiles or data files can efficiently brute-force the passwords offline using GPU or specialized hardware, potentially compromising long-term cryptographic keys and encrypted data.

Technologies: [Jahlives Openssl Encrypt](https://junglewise.ai/threats/technologies/openssl-encrypt). Vendors: [Jahlives](https://junglewise.ai/threats/vendors/jahlives).

## Quick answers

**Is CVE-2026-81718 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-81718 being exploited in the wild.

**How severe is CVE-2026-81718?** High severity, with a CVSS score of 7.5, published 27 August 2026.

**Which products and versions are affected?** Jahlives Openssl Encrypt before 1.4.9.

**Is there a fix for CVE-2026-81718?** A patch was published on 2026: Version 1.4.9 released with Argon2id and AEAD-based fixes Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-81718 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-81718?** Check whether you run Jahlives Openssl Encrypt at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a weak cryptographic parameter implementation (CWE-326) in the PBKDF2-HMAC-SHA256 key derivation function used in two contexts: (1) protecting PQC (post-quantum cryptography) keyfiles with only 100,000 iterations, falling below OWASP security recommendations of 600,000+ iterations; and (2) verifying dual-encryption file passwords using only 10,000 iterations stored in cleartext metadata. An attacker with network access can obtain keyfiles or encrypted files, then perform offline password brute-force attacks accelerated by GPUs or ASICs. The fix, released in version 1.4.9, transitions new keyfiles to Argon2id (a stronger KDF) while maintaining backward compatibility with existing PBKDF2-protected keyfiles, and removes reliance on the weak verifier in favor of AEAD authentication tags.

## Affected products

- jahlives openssl_encrypt before 1.4.9

## Timeline

- 2026-08-27: disclosed: CVE-2026-81718 published; GitHub advisory GHSA-fmjx-p826-6fvr published 2026-08-12
- 2026: patched: Version 1.4.9 released with Argon2id and AEAD-based fixes

## References

- [https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-fmjx-p826-6fvr](https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-fmjx-p826-6fvr)
- [https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-weak-cryptographic-parameters](https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-weak-cryptographic-parameters)

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