CVE-2026-4159
Received Received - Intake
Out-of-Bounds Heap Read in wolfSSL PKCS7 EnvelopedData

Publication date: 2026-03-19

Last updated on: 2026-04-29

Assigner: wolfSSL Inc.

Description
1-byte OOB heap read in wc_PKCS7_DecodeEnvelopedData via zero-length encrypted content. A vulnerability existed in wolfSSL 5.8.4 and earlier, where a 1-byte out-of-bounds heap read in wc_PKCS7_DecodeEnvelopedData could be triggered by a crafted CMS EnvelopedData message with zero-length encrypted content. Note that PKCS7 support is disabled by default.
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Meta Information
Published
2026-03-19
Last Modified
2026-04-29
Generated
2026-06-16
AI Q&A
2026-03-20
EPSS Evaluated
2026-06-14
NVD
CVE-2026-4159
EUVD
EUVD-2026-13233
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
wolfssl wolfssl to 5.9.0 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-125 The product reads data past the end, or before the beginning, of the intended buffer.
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Executive Summary

This vulnerability is a 1-byte out-of-bounds (OOB) heap read in the function wc_PKCS7_DecodeEnvelopedData within wolfSSL versions 5.8.4 and earlier. It occurs when processing a specially crafted CMS EnvelopedData message that contains zero-length encrypted content. This means the software reads one byte beyond the allocated memory buffer, which can lead to unexpected behavior or information disclosure.

It is important to note that PKCS7 support is disabled by default in wolfSSL, so this vulnerability only affects systems where PKCS7 is enabled.

Impact Analysis

The impact of this vulnerability is relatively low, as indicated by its CVSS base score of 1.2. It involves a 1-byte out-of-bounds heap read, which could potentially lead to minor information disclosure or cause a crash. However, it requires a locally accessible attacker (AV:L) with low attack complexity and partial attack type.

Since PKCS7 support is disabled by default, the vulnerability only affects systems that have explicitly enabled this feature and process crafted CMS EnvelopedData messages with zero-length encrypted content.

Compliance Impact

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Detection Guidance

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Mitigation Strategies

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