Security Resilience

CVE-2026-94417

Wolfssl ≤ 5.9.2

Published
27 September 2026
Modified
29 September 2026
CVSS Score v4 2.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/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 Score 0.0015 4th percentile
Risk Priority 20 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-2026-94417 is a low-severity Improper Check for Certificate Revocation (CWE-299) vulnerability in Wolfssl Wolfssl. Its CVSS base score is 2.3 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Junk Data (T1001.001); ranked at the 4th 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 IA-5 (Authenticator Management) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

When an application enables both OCSP and CRL revocation checking on one WOLFSSL_CTX or certificate manager, wolfSSL skips the CRL check for any peer certificate that carries no Authority Information Access OCSP URL, and accepts a certificate the loaded CRL…

more

lists as revoked. The soft-fail policy for a missing responder collapses the OCSP result onto success before the code decides whether the CRL fallback is still needed, so "no responder exists" becomes indistinguishable from "the responder answered good". Affected builds define both HAVE_OCSP and HAVE_CRL: --enable-ocsp --enable-crl directly, and implicitly --enable-all, --enable-distro, --enable-curl, --enable-nginx, --enable-haproxy, --enable-stunnel, --enable-lighty, --enable-wpas, --enable-strongswan, --enable-mosquitto, --enable-jni, --enable-openvpn and --enable-krb. An application is affected only if it calls both wolfSSL_CTX_EnableOCSP() (or wolfSSL_EnableOCSP() / wolfSSL_CertManagerEnableOCSP()) and wolfSSL_CTX_EnableCRL() (or the equivalents) with a CRL loaded; an application that uses OCSP stapling alone through wolfSSL_CTX_EnableOCSPStapling() is not affected, because that sets up a separate OCSP instance. The defect sits in ProcessPeerCerts() and is reachable over TLS 1.0 through TLS 1.3 and DTLS, both on a client verifying a server certificate and on a server verifying a client certificate under mutual or post-handshake authentication. When the skipped check falls on a chain certificate rather than the leaf, the unchecked intermediate is promoted into the certificate manager and stays a trusted signer for every later connection on that context, so an affected long-running process needs its WOLFSSL_CTX torn down and not only its library replaced. All wolfSSL versions from 5.9.2 and earlier are affected; on versions 5.9.1 and 5.9.2 the WOLFSSL_OCSP_CHECKALL configuration fails closed with OCSP_NEED_URL, which leaves wolfSSL_CTX_EnableOCSP() without CHECKALL as the exposed configuration on 5.9.2.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.001 Junk Data Command And Control
Adversaries may add junk data to protocols used for command and control to make detection more difficult.
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
T1003.006 DCSync Credential Access
Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…
T1003.007 Proc Filesystem Credential Access
Adversaries may gather credentials from the proc filesystem or `/proc`.
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
T1011.001 Exfiltration Over Bluetooth Exfiltration
Adversaries may attempt to exfiltrate data over Bluetooth rather than the command and control channel.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-6679Same product: Wolfssl Wolfssl
CVE-2026-55958Same product: Wolfssl Wolfssl
CVE-2023-6936Same product: Wolfssl Wolfssl
CVE-2026-6681Same product: Wolfssl Wolfssl
CVE-2026-7531Same product: Wolfssl Wolfssl
CVE-2026-5477Same product: Wolfssl Wolfssl
CVE-2026-5187Same product: Wolfssl Wolfssl
CVE-2026-6092Same product: Wolfssl Wolfssl
CVE-2024-1543Same product: Wolfssl Wolfssl
CVE-2025-7394Same product: Wolfssl Wolfssl

Affected Assets

wolfssl
wolfssl
≤ 5.9.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V12.1.4

Mitigating Controls (NIST 800-53 r5) AI

Authenticator management requires verification and lifecycle handling of certificates, which structurally prevents use of revoked ones when revocation status is part of the process.

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.

PR.AA-03 partial match
blocks

Certificate-based authentication requires valid, non-revoked certificates; proper revocation checking is a core implementation detail of this control.

PR.DS-02 partial match
blocks

Protecting data-in-transit commonly relies on TLS certificate validation that includes revocation status checks.

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.

blocks

A.8.24 mandates proper use of cryptography, key management and certificate handling where cryptography is applied, but does not require or enforce any check of a certificate's revocation status; the weakness (and its exploitability) can remain fully present even in a system that faithfully follows the clause.

prevents

Secure coding practices should include proper certificate revocation verification.

finds

Security testing can detect missing or incorrect certificate revocation checks.

References