CVE-2026-6966CWE-347

CVE-2026-6966

Medium · published April 25, 2026

CVSS v3.1
5.3
EPSS
0%
Percentile
19.7
In the wild
Unconfirmed
What it is

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 signature, causing the client to accept forged delegated role metadata.

We recommend you upgrade to tough-v0.22.0 / tuftool-v0.15.0.

The record
Technical detail
CVSS v3.1
5.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00283 · 19.7th percentile
Weakness
CWE-347 · Improper Verification of Cryptographic Signature
Published
2026-04-25T00:16Z
Affected products (2)
ProductVersionsFixed in
amazon/tough< 0.22.00.22.0
amazon/tuftool< 0.15.00.15.0
References (6)
https://aws.amazon.com/security/security-bulletins/2026-019-aws/ · ff89ba41-3aa1-4d27-914a-91399e9639e5https://crates.io/crates/tough/0.22.0 · ff89ba41-3aa1-4d27-914a-91399e9639e5https://crates.io/crates/tuftool/0.15.0 · ff89ba41-3aa1-4d27-914a-91399e9639e5https://github.com/awslabs/tough/releases/tag/tough-v0.22.0 · ff89ba41-3aa1-4d27-914a-91399e9639e5https://github.com/awslabs/tough/releases/tag/tuftool-v0.15.0 · ff89ba41-3aa1-4d27-914a-91399e9639e5https://github.com/awslabs/tough/security/advisories/GHSA-8m7c-8m39-rv4x · ff89ba41-3aa1-4d27-914a-91399e9639e5
EPSS history
Timeline
  • 24 APR 19:38Z
    Signature Threshold Bypass in awslabs/tough Delegated Roles
    cvelistv5