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 signature, causing the client to accept forged delegated role metadata. We recommend you upgrade to tough-v0.22.0 / tuftool-v0.15.0.

CVSS 4.0

7.0CVSS: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 3.1

6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

EPSS

0.3% chance of exploitation in the next 30 days; higher than 20% of CVEs (scores of 2026-10-25)

CWE

CWE-347

Published

2026-04-24

Modified

2026-10-20

Record from

the NVD, synced 2026-10-21

Affected

• amazon:tough
• amazon:tuftool

Packages (OSV)

References

• https://aws.amazon.com/security/security-bulletins/2026-019-aws/
• https://crates.io/crates/tough/0.22.0
• https://crates.io/crates/tuftool/0.15.0
• https://github.com/awslabs/tough/releases/tag/tough-v0.22.0
• https://github.com/awslabs/tough/releases/tag/tuftool-v0.15.0

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