ToughApplication · Amazon
CVE-2026-6966
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedImproper 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe Tough framework (AWS Labs) implementing The Update Framework (TUF) fails to verify cryptographic signature uniqueness during delegated role validation. An authenticated remote attacker can bypass the signature threshold by duplicating a valid signature, causing the client to accept forged delegated role metadata.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
ToughApplication
< 0.22.0
TuftoolApplication
< 0.15.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Check Amazon Tough versionRun 'cargo tree -p tough' or check Cargo.lock for the tough package version, or use 'pip show amazon-tough' if installed via pipAffected if Version is below 0.22.0
-
Check Amazon Tuftool versionRun 'tuftool --version' or check Cargo.lock for the tuftool package version, or use 'pip show tuftool' if installed via pipAffected if Version is below 0.15.0
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Identify use of delegated rolesInspect your TUF repository metadata for any delegated role entries (targets delegation sections in root.json or snapshot.json)Affected if Delegated roles are defined in your metadata and the version is vulnerable
You are affected if you use Amazon Tough or Tuftool with a version below 0.22.0 or 0.15.0 respectively, and your repository configuration includes delegated roles.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped0.15.00.22.0
Upgrade to tough-v0.22.0 or tuftool-v0.15.0 which includes proper signature uniqueness verification for delegated role validation.
tough-v0.22.0 / tuftool-v0.15.0
- Check the current version of tough and/or tuftool in your project by running `cargo tree | grep -E 'tough|tuftool'`
- Update your Cargo.toml file to specify the fixed versions: change `tough = "<0.22.0"` to `tugh = "0.22.0"` and/or change `tuftool = "<0.15.0"` to `tuftool = "0.15.0"`
- Run `cargo update` to update the dependency lockfile with the new versions
- Run `cargo build` or `cargo test` to compile and verify the upgrade works correctly
- Deploy the updated application
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Tough
Scoped from the published advisory
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-6966 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-6966 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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