CVE-2026-6091

MEDIUM

Partial-chain verification accepts untrusted intermediate as trust anchor

Title source: cna

Description

Partial-chain certificate verification may accept chains that terminate at a peer-supplied, untrusted intermediate certificate rather than a trusted anchor. An attacker could present a chain that ends at an intermediate they control and have it accepted as valid. This affects the OpenSSL compatibility certificate-path-building path (wolfSSL_X509_verify_cert / X509_STORE, OPENSSL_EXTRA) when the X509_V_FLAG_PARTIAL_CHAIN verify flag is enabled.

References (2)

Core 2

Core References

Patch patch

https://github.com/wolfSSL/wolfssl/pull/10170

https://www.wolfssl.com/docs/security-vulnerabilities/

Scores

CVSS v3 6.5

EPSS 0.0012

EPSS Percentile 2.2%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-295

Status published

Products (2)

wolfSSL/wolfSSL 5.7.4 - 5.9.1

wolfssl/wolfssl 5.7.4 - 5.9.2

Published Jun 25, 2026

Tracked Since Jun 25, 2026