GHSA-hfpc-8r3f-gw53: aws-lc-sys (CVE-2026-3338)

PKCS7_verify Signature Validation Bypass in AWS-LC

CVSS 8.7 HighEPSS 0.0078 · 56th percentile

Published by the GitHub Advisory Database at 2 Mar 2026, 12:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

Package	Ecosystem	Affected	Fixed in
aws-lc-sys	crates.io	>=0.24.0, <0.38.0	0.38.0

Identifiers

GHSA-hfpc-8r3f-gw53 · CVE-2026-3338 · GHSA-jchq-39cv-q4wj · RUSTSEC-2026-0047

Weakness (CWE)

CWE-347

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

The aws-lc-sys crate, versions 0.24.0 up to but not including 0.38.0, has an improper signature validation flaw in PKCS7_verify() when processing PKCS7 objects with Authenticated Attributes. An unauthenticated attacker can bypass signature verification. Upgrade aws-lc-sys to 0.38.0 or later; the source lists no workaround.

Written 8 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
8.7	High	4.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N	CNA (AMZN)

CISA KEV Not listed.
EPSS 0.0078, the 56th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 15:17 UTC First seen by agentprime
31 Oct 2026, 15:17 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.