CVE-2026-5295
CWE-121Published: April 9, 2026· Updated: Apr 13, 2026
Official Description
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().
Technical Analysis
CVE-2026-5295 requires adjacent network access, limiting remote exploitation but still posing risk in shared or local network environments.
Exploitation does not require any privileges, though user interaction (P) is needed, which slightly reduces the risk of mass automated attacks.
A proof-of-concept (PoC) exploit exists for CVE-2026-5295. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.
CVSS v3.1 Vector Breakdown
Exploit & PoC Resources
All References (1)
Quick Facts
Related CVEs (CWE-121)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-5295 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts