SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2026-3338

Improper signature validation in PKCS7_verify() in AWS-LC allows an unauthenticated user to bypass signature verification when processing PKCS7 objects with Authenticated Attributes.

HIGH 8.7EPSS 0.78%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.78%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Improper signature validation in PKCS7_verify() in AWS-LC allows an unauthenticated user to bypass signature verification when processing PKCS7 objects with Authenticated Attributes. Customers of AWS services do not need to take action. Applications using AWS-LC should upgrade to AWS-LC version 1.69.0.

CVSS 4.0
8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.78% probability · 54th percentile
CISA KEV
Not listed
Weakness
CWE-347
Affected
amazon/aws-lc-sys · amazon/aws libcrypto
Source
ff89ba41-3aa1-4d27-914a-91399e9639e5

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