# CVE-2026-81720: openssl_encrypt memory exhaustion in identity file protection block

Source: https://junglewise.ai/threats/cve-2026-81720-openssl-encrypt-memory-exhaustion-in-identity-file-protection  
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-2026-81720 · Severity: medium · CVSS 6.2 · Published 2026-08-27

openssl_encrypt is a Python library for encrypting and decrypting identity files using password protection. A flaw in how it validates memory parameters in encrypted identity files allows an attacker with write access to the local identity store to craft a malicious identity file that consumes excessive memory, causing the system to crash when the user attempts to unlock the identity before authentication.

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

## Quick answers

**Is CVE-2026-81720 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-81720 being exploited in the wild.

**How severe is CVE-2026-81720?** Medium severity, with a CVSS score of 6.2, published 27 August 2026.

**Which products and versions are affected?** Jahlives Openssl Encrypt before 1.4.9; openssl-encrypt (PyPI) ECOSYSTEM:introduced=0,fixed=1.4.9.

**Is there a fix for CVE-2026-81720?** Yes. openssl-encrypt (PyPI): upgrade to 1.4.9 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-81720 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-81720?** Check whether you run Jahlives Openssl Encrypt or openssl-encrypt (PyPI) 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.

## How to fix

- openssl-encrypt (PyPI): upgrade to 1.4.9 or later

  ```sh
  pip install "openssl-encrypt>=1.4.9"
  ```


## Technical details

The vulnerability is a resource exhaustion flaw (CWE-400) in the PasswordProtectionConfig.from_dict method, which reads the memory_cost parameter from an identity file's protection block without validating an upper bound. The _derive_key function then passes this unconstrained value to Argon2 (hash_secret_raw) for key derivation before the AEAD tag has authenticated the private key data. An attacker with write access to the local identity store or who can trick a user into loading a malicious identity file can supply an extremely large memory_cost value that causes out-of-memory conditions and system crash. The vulnerability is pre-authentication, meaning it can be triggered before the user is authenticated. Fixed in version 1.4.9 by clamping the Argon2 cost parameters (memory_cost ≤ 2 GiB, time_cost ≤ 64, parallelism ≤ 16).

## Affected products

- jahlives openssl_encrypt before 1.4.9

## Identifiers

- CVE-2026-81720
- PYSEC-2026-3965

## Timeline

- 2026-08-12: disclosed
- 2026-08-27: advisory
- 2026: patched: fixed in version 1.4.9

## References

- [https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-783h-8q2f-f762](https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-783h-8q2f-f762)
- [https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-denial-of-service-via-unbounded-argon2](https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-denial-of-service-via-unbounded-argon2)

## Related threats

- [openssl_encrypt KDF cost parameter validation bypass](https://junglewise.ai/threats/cve-2026-81721-openssl-encrypt-kdf-cost-parameter-validation-bypass)
- [openssl_encrypt arbitrary code execution via plugin signature bypass](https://junglewise.ai/threats/cve-2026-81719-openssl-encrypt-arbitrary-code-execution-via-plugin-signature)
- [openssl_encrypt weak PBKDF2 parameters in keyfile encryption](https://junglewise.ai/threats/cve-2026-81718-openssl-encrypt-weak-pbkdf2-parameters-in-keyfile-encryption)
- [openssl_encrypt USB drive integrity bypass with fixed KDF salt](https://junglewise.ai/threats/cve-2026-81717-openssl-encrypt-usb-drive-integrity-bypass-with-fixed-kdf-salt)
- [openssl-encrypt path traversal in PluginSandbox](https://junglewise.ai/threats/cve-2026-81716-openssl-encrypt-path-traversal-in-pluginsandbox)