diff --git a/go/osv/ecosystem/dhi.go b/go/osv/ecosystem/dhi.go
new file mode 100644
index 00000000000..7bee4eb76e5
--- /dev/null
+++ b/go/osv/ecosystem/dhi.go
@@ -0,0 +1,83 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ecosystem
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/ossf/osv-schema/bindings/go/osvconstants"
+)
+
+// dhiEcosystem represents "Docker Hardened Images:<lineage>:<release>"
+// advisories (e.g. "Docker Hardened Images:Alpine:3.23",
+// "Docker Hardened Images:Debian:trixie"). DHI OS packages are repackaged
+// Alpine (apk) and Debian (dpkg) packages that keep their upstream version
+// syntax (e.g. "8.4.0-r0", "7.88.1-10+deb13u2"), so version handling delegates
+// to the lineage ecosystem named in the suffix, resolved lazily via the
+// Provider to avoid a package-init cycle.
+type dhiEcosystem struct {
+	p      *Provider
+	suffix string
+}
+
+var _ Ecosystem = dhiEcosystem{}
+
+func dhiFactory(p *Provider, suffix string) Ecosystem {
+	lineage, _, _ := strings.Cut(suffix, ":")
+	if suffix == "" || lineage == string(osvconstants.EcosystemDockerHardenedImages) {
+		// Bare "Docker Hardened Images" or a self-referential suffix is malformed.
+		return nil
+	}
+
+	return dhiEcosystem{p: p, suffix: suffix}
+}
+
+// resolve looks up the lineage ecosystem named by the suffix (e.g. "Alpine:3.23"
+// or "Debian:trixie") on demand. Inner is unwrapped to avoid double-wrapping the
+// resulting Version (which would fail to compare against a singly-wrapped
+// Version from the same inner ecosystem).
+func (e dhiEcosystem) resolve() (Ecosystem, error) {
+	inner, ok := e.p.Get(e.suffix)
+	if !ok {
+		return nil, fmt.Errorf("unknown Docker Hardened Images lineage ecosystem %q", e.suffix)
+	}
+
+	return unwrap(inner), nil
+}
+
+func (e dhiEcosystem) Parse(version string) (Version, error) {
+	inner, err := e.resolve()
+	if err != nil {
+		return nil, err
+	}
+
+	return inner.Parse(version)
+}
+
+func (e dhiEcosystem) Coarse(version string) (string, error) {
+	inner, err := e.resolve()
+	if err != nil {
+		return "", err
+	}
+
+	return inner.Coarse(version)
+}
+
+// IsSemver always returns false: DHI advisories use ECOSYSTEM ranges, and DHI
+// versions follow apk/dpkg ordering rather than SemVer.
+func (e dhiEcosystem) IsSemver() bool {
+	return false
+}
diff --git a/go/osv/ecosystem/dhi_test.go b/go/osv/ecosystem/dhi_test.go
new file mode 100644
index 00000000000..ba8bbc45cb5
--- /dev/null
+++ b/go/osv/ecosystem/dhi_test.go
@@ -0,0 +1,175 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ecosystem
+
+import (
+	"testing"
+)
+
+func TestDHIEcosystem_DelegatesToInner(t *testing.T) {
+	p := NewProvider(nil)
+
+	cases := []struct {
+		name      string
+		ecosystem string
+	}{
+		{"Alpine", "Docker Hardened Images:Alpine:3.23"},
+		{"Debian", "Docker Hardened Images:Debian:trixie"},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if _, ok := p.Get(tc.ecosystem); !ok {
+				t.Fatalf("Provider.Get(%q) = ok=false, want true", tc.ecosystem)
+			}
+		})
+	}
+}
+
+func TestDHIEcosystem_Malformed(t *testing.T) {
+	p := NewProvider(nil)
+	cases := []string{
+		// Bare "Docker Hardened Images" with no lineage suffix.
+		"Docker Hardened Images",
+		"Docker Hardened Images:",
+		// Self-referential suffix.
+		"Docker Hardened Images:Docker Hardened Images",
+	}
+	for _, ecosystem := range cases {
+		t.Run(ecosystem, func(t *testing.T) {
+			if e, ok := p.Get(ecosystem); ok {
+				t.Errorf("Provider.Get(%q) = (%v, true), want (_, false)", ecosystem, e)
+			}
+		})
+	}
+}
+
+// IsSemver is false: DHI uses ECOSYSTEM ranges, not SEMVER.
+func TestDHIEcosystem_IsSemverFalse(t *testing.T) {
+	p := NewProvider(nil)
+	e, ok := p.Get("Docker Hardened Images:Alpine:3.23")
+	if !ok {
+		t.Fatalf("Docker Hardened Images:Alpine:3.23 not found")
+	}
+	if e.IsSemver() {
+		t.Errorf("IsSemver() = true, want false")
+	}
+}
+
+// The Alpine lineage sorts with apk semantics, not SemVer. In particular the
+// "-rN" package release is ordered numerically (r2 < r10); a SemVer comparison
+// would invert this by comparing the prerelease identifiers "r10" and "r2"
+// lexically. Results also match the plain Alpine parser.
+func TestDHIEcosystem_AlpineLineage(t *testing.T) {
+	p := NewProvider(nil)
+
+	dhi, ok := p.Get("Docker Hardened Images:Alpine:3.23")
+	if !ok {
+		t.Fatalf("Docker Hardened Images:Alpine:3.23 not found")
+	}
+	alpine, ok := p.Get("Alpine:3.23")
+	if !ok {
+		t.Fatalf("Alpine:3.23 not found")
+	}
+
+	v1, err := dhi.Parse("8.4.0-r0")
+	if err != nil {
+		t.Fatalf("dhi.Parse(8.4.0-r0): %v", err)
+	}
+	v2, err := dhi.Parse("8.5.0-r0")
+	if err != nil {
+		t.Fatalf("dhi.Parse(8.5.0-r0): %v", err)
+	}
+	if c, err := v1.Compare(v2); err != nil || c != -1 {
+		t.Errorf("Compare(8.4.0-r0, 8.5.0-r0) = (%d, %v), want (-1, nil)", c, err)
+	}
+
+	// apk orders the -rN release numerically, unlike SemVer prerelease ordering.
+	r2, err := dhi.Parse("1.2.3-r2")
+	if err != nil {
+		t.Fatalf("dhi.Parse(1.2.3-r2): %v", err)
+	}
+	r10, err := dhi.Parse("1.2.3-r10")
+	if err != nil {
+		t.Fatalf("dhi.Parse(1.2.3-r10): %v", err)
+	}
+	if c, err := r2.Compare(r10); err != nil || c != -1 {
+		t.Errorf("Compare(1.2.3-r2, 1.2.3-r10) = (%d, %v), want (-1, nil)", c, err)
+	}
+
+	// Delegation matches the plain Alpine parser.
+	dv, err := dhi.Parse("8.4.0-r0")
+	if err != nil {
+		t.Fatalf("dhi.Parse: %v", err)
+	}
+	av, err := alpine.Parse("8.4.0-r0")
+	if err != nil {
+		t.Fatalf("alpine.Parse: %v", err)
+	}
+	if c, err := dv.Compare(av); err != nil || c != 0 {
+		t.Errorf("Compare(dhi, alpine) = (%d, %v), want (0, nil)", c, err)
+	}
+}
+
+// The Debian lineage sorts with dpkg semantics (epoch/revision aware) and
+// matches the plain Debian parser.
+func TestDHIEcosystem_DebianLineage(t *testing.T) {
+	p := NewProvider(nil)
+
+	dhi, ok := p.Get("Docker Hardened Images:Debian:trixie")
+	if !ok {
+		t.Fatalf("Docker Hardened Images:Debian:trixie not found")
+	}
+	debian, ok := p.Get("Debian:trixie")
+	if !ok {
+		t.Fatalf("Debian:trixie not found")
+	}
+
+	v1, err := dhi.Parse("7.88.1-10+deb13u1")
+	if err != nil {
+		t.Fatalf("dhi.Parse(7.88.1-10+deb13u1): %v", err)
+	}
+	v2, err := dhi.Parse("7.88.1-10+deb13u2")
+	if err != nil {
+		t.Fatalf("dhi.Parse(7.88.1-10+deb13u2): %v", err)
+	}
+	if c, err := v1.Compare(v2); err != nil || c != -1 {
+		t.Errorf("Compare(deb13u1, deb13u2) = (%d, %v), want (-1, nil)", c, err)
+	}
+
+	dv, err := dhi.Parse("7.88.1-10+deb13u2")
+	if err != nil {
+		t.Fatalf("dhi.Parse: %v", err)
+	}
+	bv, err := debian.Parse("7.88.1-10+deb13u2")
+	if err != nil {
+		t.Fatalf("debian.Parse: %v", err)
+	}
+	if c, err := dv.Compare(bv); err != nil || c != 0 {
+		t.Errorf("Compare(dhi, debian) = (%d, %v), want (0, nil)", c, err)
+	}
+}
+
+// An unknown lineage is accepted by Get (resolved lazily, mirroring TuxCare);
+// the failure surfaces at Parse time.
+func TestDHIEcosystem_UnknownLineageFailsAtParse(t *testing.T) {
+	p := NewProvider(nil)
+	e, ok := p.Get("Docker Hardened Images:NotARealEcosystem")
+	if !ok {
+		t.Fatalf("Provider.Get(Docker Hardened Images:NotARealEcosystem) = ok=false, want true")
+	}
+	if _, err := e.Parse("1.0.0"); err == nil {
+		t.Errorf("Parse on unknown lineage returned nil error, want non-nil")
+	}
+}
diff --git a/go/osv/ecosystem/ecosystem.go b/go/osv/ecosystem/ecosystem.go
index ab33883eb7a..9ae50baf1a5 100644
--- a/go/osv/ecosystem/ecosystem.go
+++ b/go/osv/ecosystem/ecosystem.go
@@ -51,7 +51,7 @@ var ecosystems = map[osvconstants.Ecosystem]ecosystemFactory{
 	osvconstants.EcosystemCRAN:                       func(p *Provider, _ string) Ecosystem { return cranEcosystem{p: p} },
 	osvconstants.EcosystemCratesIO:                   statelessFactory[semverEcosystem],
 	osvconstants.EcosystemDebian:                     debianFactory,
-	osvconstants.EcosystemDockerHardenedImages:       statelessFactory[semverEcosystem],
+	osvconstants.EcosystemDockerHardenedImages:       dhiFactory,
 	osvconstants.EcosystemEcho:                       echoFactory,
 	osvconstants.EcosystemGHC:                        func(p *Provider, _ string) Ecosystem { return ghcEcosystem{p: p} },
 	osvconstants.EcosystemGo:                         statelessFactory[semverEcosystem],