CVE-2026-5295
Stack Buffer Overflow in wolfSSL PKCS7 wc_PKCS7_DecryptOri() via Oversized OID
Severity Score
5.9
*CVSS v4
Exploit Likelihood
*EPSS
Affected Versions
*CPE
Public Exploits
0
*Multiple Sources
Exploited in Wild
-
*KEV
Decision
Track
*SSVC
Descriptions
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().
*Credits:
Sunwoo Lee, (Korea Institute of Energy Technology, KENTECH), Woohyun Choi, (Korea Institute of Energy Technology, KENTECH), Seunghyun Yoon, (Korea Institute of Energy Technology, KENTECH)
CVSS Scores
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
System
Vulnerable | Subsequent
Confidentiality
Integrity
Availability
* Common Vulnerability Scoring System
SSVC
- Decision:Track
Exploitation
Automatable
Tech. Impact
* Organization's Worst-case Scenario
Timeline
- 2026-03-31 CVE Reserved
- 2026-04-09 CVE Published
- 2026-04-14 CVE Updated
- 2026-05-11 EPSS Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
- CWE-121: Stack-based Buffer Overflow