GHSA-4v58-8p28-2rq3 CVE-2026-6967
awslabs/tough is Missing Delegated Metadata Validation
- Severity
- 0.0 / 10
- Medium · CVSS 4.0
- Exploit chance (EPSS)
- 0.25%
- Chance of exploitation in the next 30 days. Higher than 16.80% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-345 Insufficient Verification of Data Authenticity
- Fix
- Available
- 2 packages have a fixed version
Description
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 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.
Impact
The tough library, prior to 0.22.0, does not properly verify delegated target metadata. It allows someone with write access to the metadata to serve expired or otherwise invalid targets from a TUF repository which tough will then trust rather than reject.
Impacted Versions:
tough 0.9.0 through 0.21.x, tuftool through 0.14.x
Patches
This issue has been addressed in tough version 0.22.0 and tuftool version 0.15.0. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.
Workarounds
No workarounds to this issue are known.
References
- CVE-2026-6967 If there are any questions or comments about this advisory, please contact [AWS/Amazon] Security via the vulnerability reporting page or directly via email to aws-security@amazon.com. Please do not create a public GitHub issue.
Acknowledgement
Amazon Web Services Labs would like to thank Oleh Konko of 1seal for collaborating on this issue through the coordinated vulnerability disclosure process.
Affected versions
crates.io
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
tough crates.io → 0.22.0
- cargo
cargo update -p tough --precise 0.22.0
tuftool crates.io → 0.15.0
- cargo
cargo update -p tuftool --precise 0.15.0
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:L
- Attack vector
- Network
- Attack complexity
- High
- Attack requirements
- Present
- Privileges required
- Low
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- High
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- High
- Availability (subsequent systems)
- Low
CVSS 3.1 5.9
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- Low
Weakness
CWE-345: Insufficient Verification of Data Authenticity
The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-8m7c-8m39-rv4x awslabs/tough Delegated Roles have a Signature Threshold Bypass | Medium | Also affects tough |
| GHSA-j8x2-777p-23fc tough cyclic delegation graphs are not detected | Low | Also affects tough |
| GHSA-76g3-38jv-wxh4 tough timestamp metadata is cached when it fails snapshot rollback check | Medium | Also affects tough |
| GHSA-q6r9-r9pw-4cf7 tough failure to detect delegated target rollback | Medium | Also affects tough |
| GHSA-v4wr-j3w6-mxqc tough terminating targets role delegations are not respected | Medium | Also affects tough |
| GHSA-5vmp-m5v2-hx47 tough root metadata version is not checked for sequential versioning | Medium | Also affects tough |
| GHSA-r56q-vv3c-6g9c Improper sanitization of delegated role names | High | Also affects tough |
| GHSA-x3r5-q6mj-m485 Improper sanitization of target names | High | Also affects tough |
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