Vulnerability Description
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.
CVSS Score
LOW
Related Weaknesses (CWE)
References
- https://github.com/edgelesssys/contrast/security/advisories/GHSA-6c87-g9pw-78fx
- https://www.vulncheck.com/advisories/edgeless-systems-contrast-through-1.20.0-cr
FAQ
What is CVE-2026-100837?
CVE-2026-100837 is a vulnerability with a CVSS score of 3.7 (LOW). 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 us...
How severe is CVE-2026-100837?
CVE-2026-100837 has been rated LOW with a CVSS base score of 3.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-100837?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.