CVE-2026-5501
Detail
Description
wolfSSL_X509_verify_cert in the OpenSSL compatibility layer accepts a certificate chain in which the leaf's signature is not checked, if the attacker supplies an untrusted intermediate with Basic Constraints `CA:FALSE` that is legitimately signed by a trusted root. An attacker who obtains any leaf certificate from a trusted CA (e.g. a free DV cert from Let's Encrypt) can forge a certificate for any subject name with any public key and arbitrary signature bytes, and the function returns `WOLFSSL_SUCCESS` / `X509_V_OK`. The native wolfSSL TLS handshake path (`ProcessPeerCerts`) is not susceptible and the issue is limited to applications using the OpenSSL compatibility API directly, which would include integrations of wolfSSL into nginx and haproxy.
Metrics
NVD enrichment efforts reference publicly available information to associate
vector strings. CVSS information contributed by other sources is also
displayed.
CVSS 4.0 Severity and Vector Strings:
NVD assessment
not yet provided.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS 3.x Severity and Vector Strings:
Vector:
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
CVSS 2.0 Severity and Vector Strings:
Base
Score:
NVD assessment
not yet provided.
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Weakness Enumeration
| CWE-ID |
CWE Name |
Source |
|
CWE-295
|
Improper Certificate Validation |
wolfSSL Inc.
|
Change History
4 change records found show changes
CVE Modified by CISA-ADP
6/17/2026 6:59:07 AM
| Action |
Type |
Old Value |
New Value |
| Added |
SSVC |
{"timestamp":"2026-04-22T03:55:48.544190Z","id":"CVE-2026-5501","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}
|
CVE Modified by wolfSSL Inc.
6/17/2026 6:59:07 AM
| Action |
Type |
Old Value |
New Value |
| Added |
Affected |
[{"vendor":"wolfSSL","product":"wolfSSL","defaultStatus":"unaffected","modules":["wolfSSL_X509_verify_cert"],"programFiles":["src/x509_str.c"],"versions":[{"version":"0","lessThanOrEqual":"5.9.0","versionType":"semver","status":"affected"}]}]
|
Initial Analysis by NIST
4/27/2026 1:57:21 PM
| Action |
Type |
Old Value |
New Value |
| Added |
CVSS V3.1 |
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
|
| Added |
CPE Configuration |
OR
*cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:* versions up to (including) 5.9.0
|
| Added |
Reference Type |
wolfSSL Inc.: https://github.com/wolfSSL/wolfssl/pull/10102 Types: Issue Tracking
|
New CVE Received from wolfSSL Inc.
4/10/2026 12:17:17 AM
| Action |
Type |
Old Value |
New Value |
| Added |
Description |
wolfSSL_X509_verify_cert in the OpenSSL compatibility layer accepts a certificate chain in which the leaf's signature is not checked, if the attacker supplies an untrusted intermediate with Basic Constraints `CA:FALSE` that is legitimately signed by a trusted root. An attacker who obtains any leaf certificate from a trusted CA (e.g. a free DV cert from Let's Encrypt) can forge a certificate for any subject name with any public key and arbitrary signature bytes, and the function returns `WOLFSSL_SUCCESS` / `X509_V_OK`. The native wolfSSL TLS handshake path (`ProcessPeerCerts`) is not susceptible and the issue is limited to applications using the OpenSSL compatibility API directly, which would include integrations of wolfSSL into nginx and haproxy.
|
| Added |
CVSS V4.0 |
AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/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
|
| Added |
CWE |
CWE-295
|
| Added |
Reference |
https://github.com/wolfSSL/wolfssl/pull/10102
|
Quick Info
CVE Dictionary Entry: CVE-2026-5501 NVD
Published Date: 04/10/2026 NVD
Last Modified: 06/17/2026
Source: wolfSSL Inc.
|
