CVE-2026-5500 - Vulnerability Details - OpenCVE

wolfSSL's wc_PKCS7_DecodeAuthEnvelopedData() does not properly sanitize the AES-GCM authentication tag length received and has no lower bounds check. A man-in-the-middle can therefore truncate the mac field from 16 bytes to 1 byte, reducing the tag check from 2⁻¹²⁸ to 2⁻⁸.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

No data.

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References

Link	Providers
https://github.com/wolfSSL/wolfssl/pull/10102

History

Fri, 10 Apr 2026 03:45:00 +0000

Type	Values Removed	Values Added
Description		wolfSSL's wc_PKCS7_DecodeAuthEnvelopedData() does not properly sanitize the AES-GCM authentication tag length received and has no lower bounds check. A man-in-the-middle can therefore truncate the mac field from 16 bytes to 1 byte, reducing the tag check from 2⁻¹²⁸ to 2⁻⁸.
Title		Improper Validation of AES-GCM Authentication Tag Length in PKCS#7 Envelope Allows Authentication Bypass
Weaknesses		CWE-20
References		https://github.com/wolfSSL/wolfssl/pull/10102
Metrics		cvssV4_0 `{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}`

Projects

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MITRE

Status: PUBLISHED

Assigner: wolfSSL

Published: 2026-04-10T03:10:25.671Z

Updated: 2026-04-10T03:10:25.671Z

Reserved: 2026-04-03T15:33:05.734Z

Link: CVE-2026-5500

Vulnrichment

No data.

NVD

Status : Received

Published: 2026-04-10T04:17:17.080

Modified: 2026-04-10T04:17:17.080

Link: CVE-2026-5500

Redhat

No data.

OpenCVE Enrichment

No data.

Weaknesses

CWE-20

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