Pre-authentication hang via unbounded KDF iterations
Published Aug 27, 2026 · Updated Aug 27, 2026
Uncontrolled resource consumption in OpenSSL Encrypt 1.4.8 and earlier allows attackers to hang decryption with a crafted file. The decrypt path accepts KDF iteration counts from unauthenticated file metadata, checks only estimated memory, and begins the attacker-selected work before verifying the password. The file must be opened for decryption; one extreme Argon2 or hash round count can pin a CPU core for an unbounded period, especially in unattended or batch operation.
Summary
What happened
Uncontrolled resource consumption in OpenSSL Encrypt 1.4.8 and earlier allows attackers to hang decryption with a crafted file. The decrypt path accepts KDF iteration counts from unauthenticated file metadata, checks only estimated memory, and begins the attacker-selected work before verifying the password. The file must be opened for decryption; one extreme Argon2 or hash round count can pin a CPU core for an unbounded period, especially in unattended or batch operation.
The record
- CVE
- CVE-2026-81687
- Published
- Aug 27, 2026
- Updated
- Aug 27, 2026
- Vendor
- jahlives
- Product
- OpenSSL Encrypt
- Classifications
- CWE-400, T1499
- Attack vector
- Unavailable
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 27, 2026CVE publishedPublication date reported by the CVE source.
- Aug 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <1.4.9
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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