CVE-2026-0819
Stack Buffer Overflow in wolfSSL PKCS7 SignedData Encoding
Publication date: 2026-03-19
Last updated on: 2026-04-29
Assigner: wolfSSL Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| wolfssl | wolfssl | From 5.5.0 (inc) to 5.9.0 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-787 | The product writes data past the end, or before the beginning, of the intended buffer. |
| CWE-121 | A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a stack buffer overflow in wolfSSL's PKCS7 SignedData encoding functionality. Specifically, when adding custom signed attributes, the code incorrectly uses the total count of signed attributes instead of the remaining available space in a fixed-size array. This causes the EncodeAttributes() function to write beyond the bounds of the signedAttribs array, leading to stack memory corruption or heap corruption in certain builds. Exploitation requires an application to allow untrusted input to control the size of the signedAttribs array during signing operations.
How can this vulnerability impact me? :
The vulnerability can lead to memory corruption, either on the stack or heap, depending on the build configuration. This memory corruption can cause application crashes, unpredictable behavior, or potentially allow an attacker to execute arbitrary code if they can control the input that influences the signed attributes array size.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, update wolfSSL to a version that includes the fix for the signedAttribsCount handling issue.
The fix corrects the incrementation of the signedAttribsCount variable to ensure it accurately reflects the number of attributes encoded, preventing buffer overflow and memory corruption.
Ensure that your applications do not allow untrusted input to control the signedAttribs array size when calling wc_PKCS7_EncodeSignedData() or related signing functions.