Process crash via wrapped recipient value length
Published Jun 25, 2026 · Updated Jun 25, 2026
Integer underflow in wolfSSL 3.15.5 through 5.9.1 allows remote attackers to crash a process via malformed PKCS#7 OtherRecipientInfo. The parser subtracts consumed OID bytes from an attacker-controlled sequence length without first checking that the sequence is large enough, wrapping oriValueSz before advancing the index and invoking the application's decryption callback. Exploitation requires PKCS#7 processing with an OtherRecipientInfo callback; that callback receives an oversized length and unexpected data, with a process crash as the documented bounded consequence.
Summary
What happened
Integer underflow in wolfSSL 3.15.5 through 5.9.1 allows remote attackers to crash a process via malformed PKCS#7 OtherRecipientInfo. The parser subtracts consumed OID bytes from an attacker-controlled sequence length without first checking that the sequence is large enough, wrapping oriValueSz before advancing the index and invoking the application's decryption callback. Exploitation requires PKCS#7 processing with an OtherRecipientInfo callback; that callback receives an oversized length and unexpected data, with a process crash as the documented bounded consequence.
The record
- CVE
- CVE-2026-6678
- Published
- Jun 25, 2026
- Updated
- Jun 25, 2026
- Vendor
- wolfSSL
- Product
- wolfSSL
- Classifications
- CWE-191, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 25, 2026CVE publishedPublication date reported by the CVE source.
- Jun 25, 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=3.15.5 <=5.9.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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