Wolfssl EUVD-2026-21218

Q: What is the CVSS score of EUVD-2026-21218?

EUVD-2026-21218 has a CVSS 4.0 base score of 2.1 (Low). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

| CVE-2026-5772 LOW

Buffer Over-read (CWE-126)

2026-04-09 facts@wolfssl.com

GHSA-6v2v-jgg9-h79w

Buffer Overflow Wolfssl

2.1

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

2.1 LOW

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Scope

Lifecycle Timeline

EUVD ID Assigned

Apr 09, 2026 - 22:22 euvd

EUVD-2026-21218

Analysis Generated

Apr 09, 2026 - 22:22 vuln.today

CVE Published

Apr 09, 2026 - 22:16 nvd

LOW 2.1

DescriptionCVE.org

A 1-byte stack buffer over-read was identified in the MatchDomainName function (src/internal.c) during wildcard hostname validation when the LEFT_MOST_WILDCARD_ONLY flag is active. If a wildcard * exhausts the entire hostname string, the function reads one byte past the buffer without a bounds check, which could cause a crash.

AnalysisAI

Stack buffer over-read in wolfSSL's MatchDomainName function allows authenticated remote attackers to cause denial of service through a crafted wildcard hostname during TLS certificate validation when the LEFT_MOST_WILDCARD_ONLY flag is enabled. The vulnerability reads one byte past the allocated buffer when a wildcard character exhausts the entire hostname string, triggering a potential crash with very low real-world exploitation probability (EPSS and CVSS indicate limited practical risk).

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Vulnerability AssessmentAI

Risk Assessment	This is a low-priority vulnerability despite appearing on security tracking systems. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	An authenticated user or attacker with network access to a wolfSSL-based TLS service initiates a certificate validation process with a specially crafted hostname containing only a wildcard character (e.g., '*'). If user interaction (UI:P) occurs during validation-such as a client-side certificate check or manual hostname verification-and the LEFT_MOST_WILDCARD_ONLY flag is enabled, the MatchDomainName function reads one byte past its buffer, causing a stack buffer over-read that crashes the process. …
Remediation	Apply the patch from wolfSSL via GitHub pull request #10119 or upgrade to a patched version of wolfSSL released after the fix was merged. … Detailed patch versions, workarounds, and compensating controls in full report.

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EUVD-2026-21218 vulnerability details – vuln.today

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