Contrast (Edgeless Systems) through 1.20.0 performs unanchored suffix matching when selecting per-registry configuration in the imagepuller. Config.registryFor strips a single trailing dot and then uses strings.HasSuffix(hostname, fqdn) without requiring a DNS label boundary, so a registry entry such as [registries."ghcr.io."] is also applied to any host whose name merely ends in that byte sequence, including attacker-registered domains such as evilghcr.io. When an image or layer is pulled from such a sibling domain, the imagepuller sends the configured Authorization header (basic auth, registry token, or identity token), trusts the configured custom CA bundle, follows the configured mirror, and honours insecure-skip-verify (disabling TLS verification) for that host. Image integrity is not affected, as image bytes remain pinned by digest in the policy and are validated after the pull. Configurations that use a leading dot (e.g., [registries.".example.registry"]) are unaffected.
Edgeless Systems Contrast through 1.20.0 Credential Leak via Registry Suffix Matching
Problem type
Affected products
edgelesssys
<= 1.20.0 - AFFECTED
References
https://github.com/edgelesssys/contrast/security/advisories/GHSA-6c87-g9pw-78fx
https://www.vulncheck.com/advisories/edgeless-systems-contrast-through-1.20.0-credential-leak-via-registry-suffix-matching
GitHub Security Advisories
GHSA-frqc-cxqj-qxmv
Contrast (Edgeless Systems) through 1.20.0 performs unanchored suffix matching when selecting per...
https://github.com/advisories/GHSA-frqc-cxqj-qxmvContrast (Edgeless Systems) through 1.20.0 performs unanchored suffix matching when selecting per-registry configuration in the imagepuller. Config.registryFor strips a single trailing dot and then uses strings.HasSuffix(hostname, fqdn) without requiring a DNS label boundary, so a registry entry such as [registries."ghcr.io."] is also applied to any host whose name merely ends in that byte sequence, including attacker-registered domains such as evilghcr.io. When an image or layer is pulled from such a sibling domain, the imagepuller sends the configured Authorization header (basic auth, registry token, or identity token), trusts the configured custom CA bundle, follows the configured mirror, and honours insecure-skip-verify (disabling TLS verification) for that host. Image integrity is not affected, as image bytes remain pinned by digest in the policy and are validated after the pull. Configurations that use a leading dot (e.g., [registries.".example.registry"]) are unaffected.
https://github.com/edgelesssys/contrast/security/advisories/GHSA-6c87-g9pw-78fx
https://nvd.nist.gov/vuln/detail/CVE-2026-100837
https://www.vulncheck.com/advisories/edgeless-systems-contrast-through-1.20.0-credential-leak-via-registry-suffix-matching
https://github.com/advisories/GHSA-frqc-cxqj-qxmv
JSON source
https://cveawg.mitre.org/api/cve/CVE-2026-100837Click to expand
{
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"dataVersion": "5.2",
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"cveId": "CVE-2026-100837",
"assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
"assignerShortName": "VulnCheck",
"dateUpdated": "2026-09-27T01:30:05.443Z",
"dateReserved": "2026-09-26T23:23:03.410Z",
"datePublished": "2026-09-27T01:30:05.443Z",
"state": "PUBLISHED"
},
"containers": {
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"shortName": "VulnCheck",
"dateUpdated": "2026-09-27T01:30:05.443Z"
},
"datePublic": "2026-05-27T00:00:00.000Z",
"title": "Edgeless Systems Contrast through 1.20.0 Credential Leak via Registry Suffix Matching",
"descriptions": [
{
"lang": "en",
"value": "Contrast (Edgeless Systems) through 1.20.0 performs unanchored suffix matching when selecting per-registry configuration in the imagepuller. Config.registryFor strips a single trailing dot and then uses strings.HasSuffix(hostname, fqdn) without requiring a DNS label boundary, so a registry entry such as [registries.\"ghcr.io.\"] is also applied to any host whose name merely ends in that byte sequence, including attacker-registered domains such as evilghcr.io. When an image or layer is pulled from such a sibling domain, the imagepuller sends the configured Authorization header (basic auth, registry token, or identity token), trusts the configured custom CA bundle, follows the configured mirror, and honours insecure-skip-verify (disabling TLS verification) for that host. Image integrity is not affected, as image bytes remain pinned by digest in the policy and are validated after the pull. Configurations that use a leading dot (e.g., [registries.\".example.registry\"]) are unaffected."
}
],
"affected": [
{
"vendor": "edgelesssys",
"product": "contrast",
"defaultStatus": "unaffected",
"versions": [
{
"version": "0",
"status": "affected",
"versionType": "semver",
"lessThanOrEqual": "1.20.0"
}
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}
],
"problemTypes": [
{
"descriptions": [
{
"lang": "en",
"description": "Improper Validation of Unsafe Equivalence in Input",
"cweId": "CWE-1289",
"type": "CWE"
}
]
}
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"references": [
{
"url": "https://github.com/edgelesssys/contrast/security/advisories/GHSA-6c87-g9pw-78fx",
"name": "GitHub Security Advisory (GHSA-6c87-g9pw-78fx)",
"tags": [
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]
},
{
"url": "https://www.vulncheck.com/advisories/edgeless-systems-contrast-through-1.20.0-credential-leak-via-registry-suffix-matching",
"name": "VulnCheck Advisory: Edgeless Systems Contrast through 1.20.0 Credential Leak via Registry Suffix Matching",
"tags": [
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],
"metrics": [
{
"format": "CVSS"
},
{
"format": "CVSS",
"cvssV3_1": {
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"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
"attackVector": "NETWORK",
"attackComplexity": "HIGH",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"availabilityImpact": "NONE",
"baseScore": 3.7,
"baseSeverity": "LOW"
}
}
],
"credits": [
{
"lang": "en",
"value": "offset",
"type": "reporter"
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}