CVE-2026-6966 PUBLISHED

Signature Threshold Bypass in awslabs/tough Delegated Roles

Assigner: AMZN
Reserved: 24.04.2026 Published: 24.04.2026 Updated: 24.04.2026

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.

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
CVSS Score: 5.3

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	None
Privileges Required	Low	Integrity Impact	High
User Interaction	None	Availability Impact	None

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N
CVSS Score: 7

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	High	Integrity	High	Integrity	High
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

Product Status

Vendor	AWS
Product	tough
Versions	Default: unaffected Version 0.22.0 is unaffected

Vendor	AWS
Product	tuftool
Versions	Default: unaffected Version 0.15.0 is unaffected

CVE-2026-6966 PUBLISHED

Signature Threshold Bypass in awslabs/tough Delegated Roles

Metrics

Product Status

References

Problem Types

Impacts