CVE-2026-81720: openssl_encrypt before 1.4.9 Denial of Service via Unbounded Argon2
opensslencrypt before 1.4.9 fails to validate the memorycost parameter from identity file protection blocks, allowing attackers to trigger out-of-memory conditions during key derivation. Attackers with write access to local identity stores can craft malicious identity files with excessive memorycost values that cause the host to crash when unlocking identities before authentication.
Affected Software
Event History
Frequently Asked Questions
Who is realistically exposed to this denial-of-service condition?
Hosts that use affected openssl_encrypt versions to unlock identities from local identity stores are exposed if an attacker can write or modify identity files in those stores. The impact occurs during identity unlocking, before authentication.
What access does an attacker need to trigger the issue?
The attacker needs write access to a local identity store so they can craft an identity file protection block with an excessive Argon2 memory_cost value. No authentication interaction is required once the malicious file is processed.
Are default deployments affected?
The available data does not establish whether default configurations use local identity stores or allow untrusted users to write identity files. Exposure depends on whether attackers can modify those files and whether the host unlocks them.
What can be done if upgrading is not immediately possible?
Restrict write access to local identity stores and prevent untrusted users or processes from modifying identity files. Avoid unlocking identity files from untrusted or writable locations until the affected software is updated.