{"id":"ALPINE-CVE-2026-0819","details":"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-\u003esignedAttribsCount) to EncodeAttributes() instead of the remaining available space in the fixed-size signedAttribs[7] array. When an application sets pkcs7-\u003esignedAttribsSz 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.","modified":"2026-11-03T06:33:01.252923449Z","published":"2026-03-19T17:16:21.657Z","upstream":["CVE-2026-0819"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2026-0819"}],"affected":[{"package":{"name":"wolfssl","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/wolfssl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.9.1-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-0819.json"}},{"package":{"name":"wolfssl","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/wolfssl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.9.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-0819.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H"}]}