---
id: CVE-2026-6967
title: Missing Delegated Metadata Validation in awslabs/tough
summary: >-
  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 d…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L'
cvssSource: cna
cwe:
  - CWE-345
vendor: AWS
product: tough
affected:
  - tough >= 0.9.0 <= 0.21
  - tuftool <= 0.14
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-04-24T20:13:04.619106Z'
published: '2026-04-24'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T18:26:25.513Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-6967'
references:
  - url: 'https://aws.amazon.com/security/security-bulletins/2026-019-aws/'
  - url: 'https://github.com/awslabs/tough/releases/tag/tough-v0.22.0'
  - url: 'https://github.com/awslabs/tough/releases/tag/tuftool-v0.15.0'
  - url: 'https://crates.io/crates/tough/0.22.0'
  - url: 'https://crates.io/crates/tuftool/0.15.0'
  - url: 'https://github.com/awslabs/tough/security/advisories/GHSA-4v58-8p28-2rq3'
tags:
  - cve.org
epss: 0.00303
epssPercentile: 0.21636
ingestedAt: '2026-10-20T19:16:14.549Z'
---

## Overview

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.

## Affected

- `tough >= 0.9.0 <= 0.21`
- `tuftool <= 0.14`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.