CVE-2026-81687 openssl_encrypt before 1.4.9 Denial of Service via KDF
Attackers can cause denial of service by crafting files with high KDF iteration counts, forcing excessive CPU consumption during decryption.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-81687?
CVE-2026-81687 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 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.
Weakness: CWE-400
Which versions are affected by CVE-2026-81687?
How do I fix CVE-2026-81687?
No fix has been published for CVE-2026-81687 yet. Limit exposure of the affected software until one is available.
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-2026-81687 being exploited?
There is no known exploitation of CVE-2026-81687 in the wild and no public exploit code.
Sources
Also known as GHSA-fj6q-w4r8-75h7, GHSA-rv6w-7hq9-pr74.