What is CVE-2026-6966?

CVE-2026-6966 is a medium-severity vulnerability in Amazon Tough, classified under Improper Verification of Cryptographic Signature. CVSS score: 5.3/10. Published 2026-04-24.

How severe is CVE-2026-6966?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Amazon Tough

CVE-2026-6966

Improper verification of cryptographic signature uniqueness in delegated role validation in awslabs/tough before tough-v0.22.0 allows remote authenticated users to bypass the TUF signature threshold requirement by duplicating a valid signa…

EPSS: 0.000 (5.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N.

Affected products

Amazon Tough
Amazon Tuftool
Aws Tough — versions 0.22.0
Aws Tuftool — versions 0.15.0

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

References

ff89ba41-3aa1-4d27-914a-91399e9639e5 (vendor-advisory, Vendor Advisory)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (Release Notes, patch)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (Release Notes, patch)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (Product, patch)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (Product, patch)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (Vendor Advisory, third-party-advisory)

Frequently asked questions

What is CVE-2026-6966?: CVE-2026-6966 is a medium-severity vulnerability in Amazon Tough, classified under Improper Verification of Cryptographic Signature. CVSS score: 5.3/10. Published 2026-04-24.
How severe is CVE-2026-6966?: Medium severity. CVSS v3 base score is 5.3 out of 10.