Contrast's Imagepuller registryFor uses unanchored suffix matching, leaking auth credentials and trusted CA configuration to sibling-domain registries

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

3.7 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary Config.registryFor selected a per-registry credential / CA / mirror block by checking strings.HasSuffix(name, fqdn) after stripping a single trailing dot. The match has no boundary between the configured FQDN and any preceding characters in the request hostname. A registry configured as [registries."ghcr.io."] is therefore also applied to any image pulled from a host whose name happens to end in the literal byte sequence ghcr.io, including attacker-registered domains such as evilghcr.io. The imagepuller would then send the configured Authorization header (basic auth, registry token, or identity token), trust the configured custom CA bundle, follow the configured mirror, or honour insecure-skip-verify, on requests to that hostname. Prerequisites For this to be applicable, an image or layer must be pulled from a "sibling" domain ending in one of the FQDNs configured in the imagepuller config. This may occur due to malicious intent or coincidentally. Impact - Authentication…

Published by the source

1 Jul 2026, 18:43 UTC

Last modified by the source

1 Jul 2026, 18:43 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6c87-g9pw-78fx

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# Patch Next advisory brief: GHSA-6c87-g9pw-78fx

Advisory: Contrast's Imagepuller registryFor uses unanchored suffix matching, leaking auth credentials and trusted CA configuration to sibling-domain registries
IDs: GHSA-6c87-g9pw-78fx
Record: https://patchnext.com/advisories/ghsa-6c87-g9pw-78fx (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 3.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/edgelesssys/contrast 1.21.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/edgelesssys/contrast: affected <= 1.20.0; fixed in 1.21.0

## Suggested inspection (read-only)
- Go github.com/edgelesssys/contrast: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/edgelesssys/contrast.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-6c87-g9pw-78fx (GitHub-reviewed advisory GHSA-6c87-g9pw-78fx lists affected ranges: Go github.com/edgelesssys/contrast >=0 <=1.20.0)

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