Vulnerability · Published Apr 9, 2026 · Assigned by wolfSSL
CVE-2026-5295Stack Buffer Overflow in wolfSSL PKCS7 wc_PKCS7_DecryptOri() via Oversized OID
Medium 5.9
In plain English
A medium-severity stack buffer overflow in wolfSSL from wolfSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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().
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | wolfssl | 5.9.1-r0 | ALPINE-CVE-2026-5295 |
| Alpine:v3.24 | wolfssl | 5.9.1-r0 | ALPINE-CVE-2026-5295 |
| Debian:12 | wolfssl | no fix listed | DEBIAN-CVE-2026-5295 |
| Debian:13 | wolfssl | no fix listed | DEBIAN-CVE-2026-5295 |
| Ubuntu:22.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-5295 |
| Ubuntu:24.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-5295 |
| Ubuntu:25.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-5295 |
| Ubuntu:26.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-5295 |
| Ubuntu:26.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-5295 |
Affected products (as reported)
Weakness: CWE-121 · 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