CVE-2026-0819— Stack buffer overflow in PKCS7 SignedData encoding with custom signed attributes
Quick assessment
Affected
wolfSSL wolfSSL
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
wolfSSL（CyaSSL）是美国wolfSSL公司的一个针对嵌入式系统开发人员使用的小的、可移植的嵌入式SSL编程库。 wolfSSL存在安全漏洞，该漏洞源于PKCS7 SignedData编码功能存在栈缓冲区溢出，当应用程序设置pkcs7->signedAttribsSz值过大时，可能导致栈内存损坏，在WOLFSSL_SMALL_STACK构建中则导致堆损坏。
Possible ATT&CK Techniques 2 AI
T1068 · Exploitation for Privilege Escalation T1190 · Exploit Public-Facing Application
Get alerts for future matching vulnerabilities
Log in to subscribe
I. Basic Information for CVE-2026-0819
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗
Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
Stack buffer overflow in PKCS7 SignedData encoding with custom signed attributes
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:U
Source: CVE Program / CVE List V5
Vulnerability Type
栈缓冲区溢出
Source: CVE Program / CVE List V5
Vulnerability Title
wolfSSL 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
wolfSSL（CyaSSL）是美国wolfSSL公司的一个针对嵌入式系统开发人员使用的小的、可移植的嵌入式SSL编程库。 wolfSSL存在安全漏洞，该漏洞源于PKCS7 SignedData编码功能存在栈缓冲区溢出，当应用程序设置pkcs7->signedAttribsSz值过大时，可能导致栈内存损坏，在WOLFSSL_SMALL_STACK构建中则导致堆损坏。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
II. Public POCs for CVE-2026-0819
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
Premium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2026-0819
请登录查看更多情报信息。
Patches & Fixes for CVE-2026-0819 (1)
Same Patch Batch · wolfSSL · 2026-03-19 · 11 CVEs total
| CVE-2026-3547 | 7.5 HIGH | wolfSSL: out-of-bounds read (DoS) in ALPN parsing due to incomplete validation |
| CVE-2026-1005 | Integer underflow leads to out-of-bounds access in sniffer AES-GCM/CCM/ARIA-GCM decrypt pa | |
| CVE-2026-2646 | Heap buffer overflow in session parsing with wolfSSL_d2i_SSL_SESSION() function | |
| CVE-2026-2645 | Acceptance of CertificateVerify Message before ClientKeyExchange in TLS 1.2 | |
| CVE-2026-3548 | Buffer overflow in CRL number parsing in wolfSSL | |
| CVE-2026-3579 | Non-constant time multiplication subroutine __muldi3 on RISC-V RV32I | |
| CVE-2026-3580 | Compiler-induced timing leak in sp_256_get_entry_256_9 on RISC-V | |
| CVE-2026-4395 | Heap-based buffer overflow in wc_ecc_import_x963_ex KCAPI path | |
| CVE-2026-3230 | Improper key_share validation in TLS 1.3 HelloRetryRequest | |
| CVE-2026-4159 | wc_PKCS7_DecodeEnvelopedData 1 byte out-of-bounds read |
IV. Related Vulnerabilities
Same product: wolfSSL
-
CVE-2026-15442
Heap use-after-free on read during bidirectional (D)TLS shut -
CVE-2026-89102
OCSP stapling v2 multi accepts non-CA chain certificates as -
CVE-2026-89133
NameConstraints not enforced across unconstrained intermedia -
CVE-2026-89134
Subject CN name-constraint check bypassed when non-DNS SAN p -
CVE-2026-89135
Failed X509_verify_cert leaves unverified CA in shared CertM
Same vendor: wolfSSL
-
CVE-2026-15442
Heap use-after-free on read during bidirectional (D)TLS shut -
CVE-2026-89102
OCSP stapling v2 multi accepts non-CA chain certificates as -
CVE-2026-89133
NameConstraints not enforced across unconstrained intermedia -
CVE-2026-89134
Subject CN name-constraint check bypassed when non-DNS SAN p -
CVE-2026-89135
Failed X509_verify_cert leaves unverified CA in shared CertM
Same weakness: CWE-121
-
CVE-2026-66837
Apache Thrift: PHP accelerator sizes a stack buffer from a w -
CVE-2026-104611
Tenda AC9 POST Request fast_setting_internet_set stack-based -
CVE-2026-104610
Tenda HG7/HG9/HG10 Boa Web Server formLoopBack boaGetVar sta -
CVE-2026-86325
协议网关账户管理接口栈溢出漏洞 -
CVE-2026-93925
Apache Thrift: C++ `THeaderTransport::writeVarint32()` stack
V. Comments for CVE-2026-0819
No comments yet