# CVE-2026-6967: awslabs/tough is Missing Delegated Metadata Validation

Source: https://junglewise.ai/threats/cve-2026-6967-awslabs-tough-is-missing-delegated-metadata-validation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-24  
License: CC BY 4.0 with a link back

CVE-2026-6967 · Severity: medium · CVSS 5.9 · Published 2026-04-24

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.

Technologies: [Amazon Tough](https://junglewise.ai/threats/technologies/amazon-tough), [Amazon Tuftool](https://junglewise.ai/threats/technologies/amazon-tuftool), [tough (crates.io)](https://junglewise.ai/threats/technologies/crates-io-tough). Vendors: [Amazon](https://junglewise.ai/threats/vendors/amazon), [crates.io](https://junglewise.ai/threats/vendors/crates-io).

## Quick answers

**Is CVE-2026-6967 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-6967 being exploited in the wild.

**How severe is CVE-2026-6967?** Medium severity, with a CVSS score of 5.9, published 24 April 2026.

**Which products and versions are affected?** tough (crates.io) SEMVER:introduced=0.9.0,fixed=0.22.0; tuftool (crates.io) SEMVER:introduced=0,fixed=0.15.0.

**Is there a fix for CVE-2026-6967?** Yes. tough (crates.io): upgrade to 0.22.0 or later; tuftool (crates.io): upgrade to 0.15.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-6967?** Check whether you run Amazon Tough, Amazon Tuftool, tough (crates.io) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- tough (crates.io): upgrade to 0.22.0 or later

  ```sh
  cargo update -p tough
  ```

- tuftool (crates.io): upgrade to 0.15.0 or later

  ```sh
  cargo update -p tuftool
  ```


## Affected products

- Amazon Tough
- Amazon Tuftool
- tough (crates.io) SEMVER:introduced=0.9.0,fixed=0.22.0
- tuftool (crates.io) SEMVER:introduced=0,fixed=0.15.0

## Identifiers

- CVE-2026-6967
- GHSA-4v58-8p28-2rq3

## Related threats

- [Incomplete path traversal fixes in awslabs/tough before tough-v0.22.0 allow remote authenticated users with delegated…](https://junglewise.ai/threats/cve-2026-6968-incomplete-path-traversal-fixes-in-awslabs-tough-before-tough-v0)
- [awslabs/tough Delegated Roles have a Signature Threshold Bypass](https://junglewise.ai/threats/cve-2026-6966-aws-tough-and-tuftool-multiple-vulnerabilities-in-tuf)
- [tough cyclic delegation graphs are not detected](https://junglewise.ai/threats/tough-cyclic-delegation-graphs-are-not-detected-8423c397)
- [tough terminating targets role delegations are not respected](https://junglewise.ai/threats/cve-2025-2886-tough-terminating-targets-role-delegations-are-not-respected)
- [tough root metadata version is not checked for sequential versioning](https://junglewise.ai/threats/cve-2025-2885-tough-root-metadata-version-is-not-checked-for-sequential)