Vulnerability in Edgelesssys Contrast
CVE-2026-100837
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.002 (11.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 11.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-6c87-g9pw-78fx) (vendor-advisory)
- VulnCheck Advisory: Edgeless Systems Contrast through 1.20.0 Credential Leak via Registry Suffix Matching (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100837?
- CVE-2026-100837 is a low-severity vulnerability in Edgelesssys Contrast, classified under CWE-1289. CVSS score: 3.7/10. Published 2026-09-27.
- How severe is CVE-2026-100837?
- Low severity. CVSS v3 base score is 3.7 out of 10.