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ToughApplication · Amazon

CVE-2026-6967

MEDIUM · 6.5 CVSS v3.1 Published 2026-04-24
Fix available
A fix is available. Upgrade to 0.15.0 / 0.22.0 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

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 · unedited
Missing expiration, hash, and length enforcement in delegated metadata validation in awslabs/tough before tough-v0.22.0 allows remote authenticated users with delegated signing authority to bypass TUF specification integrity checks for delegated targets metadata and poison the local metadata cache, because load_delegations does not apply the same validation checks as the top-level targets metadata path. 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 confidence

The tough library before v0.22.0 fails to enforce expiration, hash, and length validation on delegated metadata during the load_delegations process, unlike the top-level targets metadata path. This allows an authenticated user with delegated signing authority to inject malicious delegated targets metadata that bypasses TUF integrity checks, poisoning the local metadata cache.

MitigationUpgrade tough to v0.22.0 or later (and tuftool to v0.15.0) to ensure delegated metadata receives the same validation checks as top-level targets.

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
Affected:>= 0.9.0, < 0.22.0
TuftoolApplication
Affected:< 0.15.0

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Check Amazon Tough library version
    Run 'pip show tough' or 'pip list | grep -i tough' to find the installed version of the tough package
    Affected if The installed version is >= 0.9.0 and < 0.22.0
  2. Check Amazon Tuftool version
    Run 'tuftool --version' if installed as a binary, or check cargo list for tuftool crate version
    Affected if The installed version is < 0.15.0
  3. Determine if delegated metadata is processed
    Review application code or configuration for calls to load_delegations or processing of TUF delegated targets metadata files
    Affected if The system loads or processes TUF delegated targets metadata (delegations from one targets role to another)
  4. Verify metadata validation behavior
    Inspect application logs or test with expired/falsified delegated metadata to observe whether validation is enforced on delegated paths
    Affected if Delegated metadata is processed without expiration, hash, or length validation being applied (unlike top-level targets)

You are affected if you use tough < 0.22.0 or tuftool < 0.15.0 AND your system processes TUF delegated metadata, since delegated targets bypass integrity checks that are enforced on top-level targets.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 0.15.0 / 0.22.0 or later
Fixed in 0.15.00.22.0
Interim mitigation

Upgrade tough to v0.22.0 or later (and tuftool to v0.15.0) to ensure delegated metadata receives the same validation checks as top-level targets.

Recommended fix High confidence

tough-v0.22.0 / tuftool-v0.15.0

  1. Update the tough dependency in Cargo.toml to version 0.22.0 or later
  2. Update the tuftool dependency in Cargo.toml to version 0.15.0 or later
  3. Run cargo update to fetch the new versions
  4. Rebuild the project with cargo build to ensure the new versions are properly integrated
  5. Verify the application functions correctly after the upgrade

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Tough Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,072.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-6967 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data