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.
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
References
- https://aws.amazon.com/security/security-bulletins/2026-005-AWS/Vendor Advisory
- https://github.com/aws/aws-lc/releases/tag/v1.69.0Release Notes
- https://github.com/aws/aws-lc/security/advisories/GHSA-jchq-39cv-q4wjVendor Advisory
- https://access.redhat.com/errata/RHSA-2026:5459
- https://access.redhat.com/security/cve/CVE-2026-3338
- https://bugzilla.redhat.com/show_bug.cgi?id=2444025
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3338.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.