Security Resilience

CVE-2026-6678

Memory Safety in Wolfssl 3.15.5 – 5.9.2

Memory Safety
Published
25 June 2026
Modified
01 July 2026
Patch / advisory
View advisory
CVSS Score v4 1.0
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:H/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:Clear
EPSS Score 0.0033 25th percentile
Risk Priority 15 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-6678 is a low-severity Wrap or Wraparound (CWE-191) vulnerability in Wolfssl Wolfssl. Its CVSS base score is 1.0 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique LSASS Memory (T1003.001); ranked at the 25th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Integer underflow in wc_PKCS7_DecryptOri when handling crafted Other Recipient Info, leading to incorrect length handling during decryption.

CWE(s)
CWE-191

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
attack.mitre.org →
T1003.003 NTDS Credential Access
Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights.
attack.mitre.org →
T1003.005 Cached Domain Credentials Credential Access
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
attack.mitre.org →
T1003.008 /etc/passwd and /etc/shadow Credential Access
Adversaries may attempt to dump the contents of <code>/etc/passwd</code> and <code>/etc/shadow</code> to enable offline password cracking.
attack.mitre.org →
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
attack.mitre.org →
T1008 Fallback Channels Command And Control
Adversaries may use fallback or alternate communication channels if the primary channel is compromised or inaccessible in order to maintain reliable command and control and to avoid data transfer thresholds.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-11931Same product: Wolfssl Wolfssl
CVE-2026-6679Same product: Wolfssl Wolfssl
CVE-2023-6936Same product: Wolfssl Wolfssl
CVE-2026-6681Same product: Wolfssl Wolfssl
CVE-2024-1543Same product: Wolfssl Wolfssl
CVE-2026-55958Same product: Wolfssl Wolfssl
CVE-2026-7531Same product: Wolfssl Wolfssl
CVE-2026-5187Same product: Wolfssl Wolfssl
CVE-2026-6291Same product: Wolfssl Wolfssl
CVE-2026-5477Same product: Wolfssl Wolfssl

Affected Assets

wolfssl
wolfssl
3.15.5 — 5.9.2

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and static/dynamic analysis directly find integer underflow defects before code is released.

SA-8 Security and Privacy Engineering Principles partial match

Security engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer underflow during subtraction.

SI-10 Information Input Validation partial match

Input validation can reject or sanitize values that would cause a subtraction to underflow the representable range.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

ID.RA-01 partial match
blocks

Vulnerability scanning and code analysis can surface underflow flaws after they are introduced.

PR.PS-02 partial match
blocks

Routine patching can remediate known underflow bugs once they are discovered in deployed software.

PR.PS-06 partial match
blocks

Secure SDLC practices directly prevent integer underflow defects via input validation, bounds checking, and static analysis.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References