A stack buffer overflow exists in wolfSSL's PKCS7 implementation in the wc_PKCS7_DecryptOri() function in wolfcrypt/src/pkcs7.c. When processing a CMS EnvelopedData message containing an OtherRecipientInfo (ORI) recipient, the function copies an ASN.1-parsed OID into a fixed 32-byte stack buffer (oriOID[MAX_OID_SZ]) via XMEMCPY without first validating that the parsed OID length does not exceed MAX_OID_SZ. A crafted CMS EnvelopedData message with an ORI recipient containing an OID longer than 32 bytes triggers a stack buffer overflow. Exploitation requires the library to be built with --enable-pkcs7 (disabled by default) and the application to have registered an ORI decrypt callback via wc_PKCS7_SetOriDecryptCb().
Published: 2026-04-09
Updated: 2026-04-09
Base Score: 6.8
Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P
Severity: Medium
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 5.9
Vector: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
Severity: Medium
EPSS: 0.00016