CVE-2026-81699 openssl_encrypt before 1.4.9 Denial of Service via unbounded KDF cost

High 8.7 Published 27 Aug 2026 Updated 1 Oct 2026

Attackers can cause denial of service by supplying crafted files with excessive KDF parameters, exhausting system resources before authentication.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-81699?

CVE-2026-81699 is a high-severity denial of service vulnerability in Jahlives Openssl Encrypt, published on 27 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

openssl_encrypt versions before 1.4.9 fail to properly validate key derivation function costs in crafted files, allowing attackers to trigger unbounded memory and CPU exhaustion during pre-authentication processing. Attackers can supply malicious files with excessive KDF parameters to exhaust system resources and crash or wedge the process before password verification occurs.

Weakness: CWE-770

Which versions are affected by CVE-2026-81699?

1 open source package ship an affected version, including openssl-encrypt. It affects 1 product.

Package	Affected	Fixed in
`openssl-encrypt` PyPI	All versions	`1.4.9`

Products include Jahlives Openssl Encrypt.

How do I fix CVE-2026-81699?

Upgrade openssl-encrypt to 1.4.9 or later.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-81699 being exploited?

There is no known exploitation of CVE-2026-81699 in the wild and no public exploit code.

All Jahlives Openssl Encrypt vulnerabilities

Sources

Also known as GHSA-jpvp-h4hw-m539, GHSA-phmr-p567-q5g6, PYSEC-2026-3961.