CVE-2026-0819
Severity CVSS v4.0:
LOW
Type:
CWE-121
Stack-based Buffer Overflow
Publication date:
19/03/2026
Last modified:
29/04/2026
Description
A stack buffer overflow vulnerability exists in wolfSSL's PKCS7 SignedData encoding functionality. In wc_PKCS7_BuildSignedAttributes(), when adding custom signed attributes, the code passes an incorrect capacity value (esd->signedAttribsCount) to EncodeAttributes() instead of the remaining available space in the fixed-size signedAttribs[7] array. When an application sets pkcs7->signedAttribsSz to a value greater than MAX_SIGNED_ATTRIBS_SZ (default 7) minus the number of default attributes already added, EncodeAttributes() writes beyond the array bounds, causing stack memory corruption. In WOLFSSL_SMALL_STACK builds, this becomes heap corruption. Exploitation requires an application that allows untrusted input to control the signedAttribs array size when calling wc_PKCS7_EncodeSignedData() or related signing functions.
Impact
Base Score 4.0
2.20
Severity 4.0
LOW
Base Score 3.x
7.10
Severity 3.x
HIGH
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:* | 5.5.0 (including) | 5.9.0 (excluding) |
To consult the complete list of CPE names with products and versions, see this page