pkcs7

About this tag
The pkcs7 tag on WindowsForum.com covers discussions about the PKCS#7 cryptographic message syntax standard, particularly in the context of security patches and vulnerabilities. Recent content highlights a critical AWS-LC patch in version 1.69.0 that fixes PKCS#7 chain validation bypasses (CVE-2026-3336 and CVE-2026-3338), where the PKCS7_verify() routine could incorrectly skip certificate chain checks for multi-signer objects. These issues allowed unauthenticated actors to subvert signature validation. The tag also touches on related cryptographic vulnerabilities like a timing side-channel in AES-CCM. Topics are relevant to developers, system administrators, and security professionals working with PKCS#7 in Windows or cross-platform environments.

  1. AWS LC Patch Fixes PKCS#7 Chain Validation in v1.69.0

    AWS’ open-source cryptographic library AWS‑LC received a pair of serious PKCS#7 validation fixes in early March 2026 after researchers reported that the library’s PKCS7_verify() routine could incorrectly bypass certificate chain validation for certain multi‑signer PKCS#7 objects, allowing...