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CVE-2026-6966
Signature Threshold Bypass in awslabs/tough Delegated Roles
High7.0EPSS 0.28%
- Published
- Updated
- Reserved
- Assigned by
- AMZN
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| AMZNCNA (assigner) | 4.0 | High7.0 | 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 |
| AMZNCNA (assigner) | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N |
| NVDNVD · Modified | 4.0 | High7.0 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.28% · top 79% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
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The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.0.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- crates.iotoughGHSA-8m7c-8m39-rv4x (opens in a new tab)
- crates.iotuftoolGHSA-8m7c-8m39-rv4x (opens in a new tab)
References (6)
- https://aws.amazon.com/security/security-bulletins/2026-019-aws/ (opens in a new tab)vendor-advisory
- https://github.com/awslabs/tough/releases/tag/tough-v0.22.0 (opens in a new tab)patch
- https://github.com/awslabs/tough/releases/tag/tuftool-v0.15.0 (opens in a new tab)patch
- https://crates.io/crates/tough/0.22.0 (opens in a new tab)patch
- https://crates.io/crates/tuftool/0.15.0 (opens in a new tab)patch
- https://github.com/awslabs/tough/security/advisories/GHSA-8m7c-8m39-rv4x (opens in a new tab)third-party-advisory
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-8m7c-8m39-rv4x (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-6966)Record last updated .