VulnerabilityAnalyzed

CVE-2026-0819

A stack buffer overflow vulnerability exists in wolfSSL's PKCS7 SignedData encoding functionality.

LOW 2.2EPSS 0.10%

Does this matter?

Lower severity and a low EPSS score (0.10%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0: 2.2 LOWCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.10% probability · 1th percentile
CISA KEV: Not listed
Weakness: CWE-121, CWE-787
Affected: wolfssl/wolfssl
Source: facts@wolfssl.com

References

https://github.com/wolfSSL/wolfssl/pull/9630Issue Tracking, Patch

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.