Heap corruption via overflowing certificate-chain allocation
Published Mar 19, 2026 · Updated Mar 19, 2026
Integer overflow in wolfssl_add_to_chain in wolfSSL before 5.9.0 allows attackers to corrupt heap memory while adding certificates. The function adds len, CERT_HEADER_SZ, and certSz in a 32-bit word without an overflow guard, allocates the wrapped size, and then writes certificate data beyond that buffer. Triggering requires a listed third-party compatibility feature and prior compromise of the application context that loads certificates; the flaw is not remotely reachable.
Summary
What happened
Integer overflow in wolfssl_add_to_chain in wolfSSL before 5.9.0 allows attackers to corrupt heap memory while adding certificates. The function adds len, CERT_HEADER_SZ, and certSz in a 32-bit word without an overflow guard, allocates the wrapped size, and then writes certificate data beyond that buffer. Triggering requires a listed third-party compatibility feature and prior compromise of the application context that loads certificates; the flaw is not remotely reachable.
The record
- CVE
- CVE-2026-3229
- Published
- Mar 19, 2026
- Updated
- Mar 19, 2026
- Vendor
- wolfSSL
- Product
- wolfSSL
- Classifications
- CWE-122
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Mar 19, 2026CVE publishedPublication date reported by the CVE source.
- Mar 19, 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?
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- Affected versionversion=0 <5.9.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
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Your stack
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