High
Signature Threshold Bypass in awslabs/tough Delegated Roles
Type: advisorySources: OSV
Improper 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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-6966
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 4 Nov 2026, 08:20 UTC · Revision 1
Source evidence
Signature Threshold Bypass in awslabs/tough Delegated Roles
core-osv · Original sourcePublished 24 Apr 2026, 19:38 UTC
Improper 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.
osv:CVE-2026-6966
Complete source record
{
"id": "7d9cb236c6210e78ee972c1c58b6dedc742dd4fbbe88c9e4774c6777436bdea1",
"url": "https://osv.dev/vulnerability/CVE-2026-6966",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Signature Threshold Bypass in awslabs/tough Delegated Roles",
"summary": "Improper 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.",
"evidence": "osv:CVE-2026-6966",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-6966",
"aliases": [
"CVE-2026-6966",
"GHSA-8m7c-8m39-rv4x"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/awslabs/tough",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "606dc87a8456c8f6e24c4a85e12b280cf2c9ca00"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:amazon:tough:*:*:*:*:*:rust:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "0.22.0"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:amazon:tuftool:*:*:*:*:*:rust:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "0.15.0"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "606dc87a8456c8f6e24c4a85e12b280cf2c9ca00"
}
],
"source": "REFERENCES_TAG",
"original_tag": "tough-v0.22.0"
},
{
"range": [
{
"fixed": "606dc87a8456c8f6e24c4a85e12b280cf2c9ca00"
}
],
"source": "REFERENCES_TAG",
"original_tag": "tuftool-v0.15.0"
}
]
}
}
],
"versions": [
"tuftool-v0.14.0",
"tough-v0.21.0",
"tough-ssm-v0.16.0",
"tough-kms-v0.13.0",
"tuftool-v0.13.0",
"tough-v0.20.0",
"tough-ssm-v0.15.0",
"tough-kms-v0.12.0",
"tuftool-v0.12.0",
"tough-v0.19.0",
"tough-ssm-v0.14.0",
"tough-kms-v0.11.0",
"olpc-cjson-v0.1.4",
"tuftool-v0.11.1",
"tuftool-v0.11.0",
"tough-v0.18.0",
"tough-ssm-v0.13.0",
"tough-kms-v0.10.0",
"tough-v0.17.1",
"tuftool-v0.10.3",
"tough-v0.17.0",
"tough-ssm-v0.12.0",
"tough-kms-v0.9.0",
"tuftool-v0.10.2",
"tough-v0.16.0",
"tough-ssm-v0.11.0",
"tough-kms-v0.8.0",
"tuftool-v0.10.1",
"tough-v0.15.0",
"tough-ssm-v0.10.0",
"tough-kms-v0.7.0",
"tuftool-v0.10.0",
"tough-v0.14.0",
"tough-ssm-v0.9.0",
"tough-kms-v0.6.0",
"tuftool-v0.9.0",
"tough-v0.13.0",
"tough-ssm-v0.8.0",
"tough-kms-v0.5.0",
"olpc-cjson-v0.1.3",
"tuftool-v0.8.2",
"tough-v0.12.5",
"tough-ssm-v0.7.2",
"tough-kms-v0.4.2",
"olpc-cjson-v0.1.2",
"tuftool-v0.8.1",
"tough-v0.12.4",
"tough-ssm-v0.7.1",
"tough-kms-v0.4.1",
"tuftool-v0.8.0",
"tough-v0.12.3",
"tough-ssm-v0.7.0",
"tough-kms-v0.4.0",
"tuftool-v0.7.2",
"tough-v0.12.2",
"tough-ssm-v0.6.6",
"tough-kms-v0.3.6",
"tuftool-v0.7.0",
"tough-v0.12.0",
"tough-ssm-v0.6.4",
"tough-kms-v0.3.4",
"tuftool-v0.6.4",
"tough-v0.11.3",
"tough-ssm-v0.6.3",
"tough-kms-v0.3.3",
"tuftool-v0.6.3",
"tough-v0.11.2",
"tough-ssm-v0.6.2",
"tough-kms-v0.3.2",
"tuftool-v0.6.2",
"tough-v0.11.1",
"tough-ssm-v0.6.1",
"tough-kms-v0.3.1",
"olpc-cjson-v0.1.1",
"tough-kms-v0.1.1",
"tuftool-v0.5.0",
"tough-v0.9.0",
"tough-ssm-v0.4.0",
"tough-kms-v0.1.0",
"tuftool-v0.4.1",
"tough-v0.8.0",
"tough-ssm-v0.3.0",
"tough-v0.7.0",
"tough-ssm-v0.2.0",
"tuftool-v0.4.0",
"tough-ssm-v0.1.0",
"tough-v0.6.0",
"tough-v0.5.0",
"tuftool-v0.3.0",
"tough-v0.4.0",
"tuftool-v0.2.0",
"tough-v0.3.0",
"tuftool-v0.1.1",
"tough-v0.2.0",
"tuftool-v0.1.0",
"tough-v0.1.0",
"olpc-cjson-v0.1.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6966.json"
}
}
],
"modified": "2026-10-31T10:31:07.447713866Z",
"provider": "osv",
"references": [
"https://aws.amazon.com/security/security-bulletins/2026-019-aws/",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6966.json",
"https://github.com/awslabs/tough/security/advisories/GHSA-8m7c-8m39-rv4x",
"https://nvd.nist.gov/vuln/detail/CVE-2026-6966",
"https://crates.io/crates/tough/0.22.0",
"https://crates.io/crates/tuftool/0.15.0",
"https://github.com/awslabs/tough/releases/tag/tough-v0.22.0",
"https://github.com/awslabs/tough/releases/tag/tuftool-v0.15.0"
],
"provider_metadata": {
"cwe_ids": [
"CWE-347"
],
"cna_assigner": "AMZN",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6966.json"
}
},
"related_cves": [
{
"value": "CVE-2026-6966",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 501100,
"published_at": "2026-04-24T19:38:24.907+00:00"
}