diff --git a/decnet/web/db/models/attackers.py b/decnet/web/db/models/attackers.py
index a13b0015..90271462 100644
--- a/decnet/web/db/models/attackers.py
+++ b/decnet/web/db/models/attackers.py
@@ -89,6 +89,14 @@ class Attacker(SQLModel, table=True):
     # last 24h" without joining to AttackerFingerprintState.
     rotation_count: int = Field(default=0)
     last_rotation_at: Optional[datetime] = Field(default=None, index=True)
+    # IPv6 link-local leak telemetry. Denormalized cache — authoritative
+    # history lives in TTPTag rows with source_kind="ipv6_leak". Kept here
+    # so the attacker drawer can render the leaked address in one query.
+    ipv6_leak_count: int = Field(default=0)
+    last_ipv6_leak_at: Optional[datetime] = Field(default=None, index=True)
+    last_ipv6_link_local: Optional[str] = Field(default=None, max_length=45)
+    last_ipv6_iid_kind: Optional[str] = Field(default=None, max_length=16)
+    last_ipv6_mac_oui: Optional[str] = Field(default=None, max_length=8)
     updated_at: datetime = Field(
         default_factory=lambda: datetime.now(timezone.utc), index=True
     )
@@ -197,6 +205,15 @@ class AttackerIdentity(SQLModel, table=True):
     tls_cert_sha256: Optional[str] = Field(
         default=None, sa_column=Column("tls_cert_sha256", Text, nullable=True)
     )
+    # JSON list[dict] — observed IPv6 link-local IIDs per identity.
+    # EUI-64-derived MACs survive VPN/IP rotation and are a stronger
+    # cluster signal than any rotatable TLS/SSH hash. Federation gossip
+    # (V2) will share these. Shape per entry:
+    #   {"iid": "fe80::aabb:ccff:fedd:eeff", "oui": "aa:bb:cc",
+    #    "kind": "eui64", "first_seen": "<ISO8601>"}
+    ipv6_link_local_iids: Optional[str] = Field(
+        default=None, sa_column=Column("ipv6_link_local_iids", Text, nullable=True)
+    )
     # Payload SimHash list — 64-bit ints serialized as hex strings.
     # SimHashes are Hamming-comparable, which is the entire reason
     # they're a list (not a set).
diff --git a/tests/web/test_attackers_ipv6_leak.py b/tests/web/test_attackers_ipv6_leak.py
new file mode 100644
index 00000000..535dd665
--- /dev/null
+++ b/tests/web/test_attackers_ipv6_leak.py
@@ -0,0 +1,212 @@
+"""Tests for IPv6 link-local leak columns on Attacker and AttackerIdentity.
+
+Verifies:
+* New fields exist with correct Optional[str] / int types (GREEN on model).
+* Defaults are correct (0 / None).
+* SQLite round-trip stores and retrieves non-None values correctly.
+* Existing columns are unaffected.
+"""
+from __future__ import annotations
+
+import json
+import uuid as _uuid
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Optional, get_type_hints
+
+import pytest
+import pytest_asyncio
+
+from decnet.web.db.factory import get_repository
+from decnet.web.db.models.attackers import Attacker, AttackerIdentity
+
+
+# ── Field presence (type-level, GREEN today) ─────────────────────────
+
+
+def test_attacker_ipv6_leak_count_is_int() -> None:
+    hints = get_type_hints(Attacker)
+    assert "ipv6_leak_count" in hints
+    assert hints["ipv6_leak_count"] == int
+
+
+def test_attacker_last_ipv6_leak_at_optional_datetime() -> None:
+    hints = get_type_hints(Attacker)
+    assert "last_ipv6_leak_at" in hints
+    assert hints["last_ipv6_leak_at"] == Optional[datetime]
+
+
+def test_attacker_last_ipv6_link_local_optional_str() -> None:
+    hints = get_type_hints(Attacker)
+    assert "last_ipv6_link_local" in hints
+    assert hints["last_ipv6_link_local"] == Optional[str]
+
+
+def test_attacker_last_ipv6_iid_kind_optional_str() -> None:
+    hints = get_type_hints(Attacker)
+    assert "last_ipv6_iid_kind" in hints
+    assert hints["last_ipv6_iid_kind"] == Optional[str]
+
+
+def test_attacker_last_ipv6_mac_oui_optional_str() -> None:
+    hints = get_type_hints(Attacker)
+    assert "last_ipv6_mac_oui" in hints
+    assert hints["last_ipv6_mac_oui"] == Optional[str]
+
+
+def test_identity_ipv6_link_local_iids_optional_str() -> None:
+    hints = get_type_hints(AttackerIdentity)
+    assert "ipv6_link_local_iids" in hints
+    assert hints["ipv6_link_local_iids"] == Optional[str]
+
+
+def test_attacker_ipv6_defaults() -> None:
+    row = Attacker(
+        uuid=str(_uuid.uuid4()),
+        ip="1.2.3.4",
+        first_seen=datetime.now(timezone.utc),
+        last_seen=datetime.now(timezone.utc),
+    )
+    assert row.ipv6_leak_count == 0
+    assert row.last_ipv6_leak_at is None
+    assert row.last_ipv6_link_local is None
+    assert row.last_ipv6_iid_kind is None
+    assert row.last_ipv6_mac_oui is None
+
+
+def test_identity_ipv6_link_local_iids_defaults_to_none() -> None:
+    row = AttackerIdentity(uuid=str(_uuid.uuid4()))
+    assert row.ipv6_link_local_iids is None
+
+
+# ── SQLite round-trips ────────────────────────────────────────────────
+
+
+@pytest_asyncio.fixture()
+async def repo(tmp_path: Path, monkeypatch):
+    monkeypatch.setenv("DECNET_DB_TYPE", "sqlite")
+    r = get_repository(db_path=str(tmp_path / "ipv6_leak_test.db"))
+    await r.initialize()
+    try:
+        yield r
+    finally:
+        engine = getattr(r, "engine", None)
+        if engine is not None:
+            try:
+                await engine.dispose()
+            except Exception:
+                pass
+
+
+def _identity(extra: dict | None = None) -> AttackerIdentity:
+    base = {
+        "uuid": str(_uuid.uuid4()),
+        "schema_version": 1,
+        "created_at": datetime.now(timezone.utc),
+        "updated_at": datetime.now(timezone.utc),
+    }
+    if extra:
+        base.update(extra)
+    return AttackerIdentity(**base)
+
+
+def _attacker(extra: dict | None = None) -> Attacker:
+    now = datetime.now(timezone.utc)
+    base = {
+        "uuid": str(_uuid.uuid4()),
+        "ip": "10.0.0.1",
+        "first_seen": now,
+        "last_seen": now,
+    }
+    if extra:
+        base.update(extra)
+    return Attacker(**base)
+
+
+@pytest.mark.asyncio
+async def test_attacker_ipv6_columns_round_trip(repo) -> None:
+    now = datetime.now(timezone.utc)
+    row = _attacker({
+        "ipv6_leak_count": 3,
+        "last_ipv6_leak_at": now,
+        "last_ipv6_link_local": "fe80::aabb:ccff:fedd:eeff",
+        "last_ipv6_iid_kind": "eui64",
+        "last_ipv6_mac_oui": "aa:bb:cc",
+    })
+    async with repo._session() as session:
+        session.add(row)
+        await session.commit()
+    async with repo._session() as session:
+        fetched = await session.get(Attacker, row.uuid)
+    assert fetched is not None
+    assert fetched.ipv6_leak_count == 3
+    assert fetched.last_ipv6_link_local == "fe80::aabb:ccff:fedd:eeff"
+    assert fetched.last_ipv6_iid_kind == "eui64"
+    assert fetched.last_ipv6_mac_oui == "aa:bb:cc"
+
+
+@pytest.mark.asyncio
+async def test_attacker_ipv6_columns_nullable(repo) -> None:
+    row = _attacker()
+    async with repo._session() as session:
+        session.add(row)
+        await session.commit()
+    async with repo._session() as session:
+        fetched = await session.get(Attacker, row.uuid)
+    assert fetched is not None
+    assert fetched.ipv6_leak_count == 0
+    assert fetched.last_ipv6_leak_at is None
+    assert fetched.last_ipv6_link_local is None
+
+
+@pytest.mark.asyncio
+async def test_identity_ipv6_link_local_iids_round_trip(repo) -> None:
+    iids = json.dumps([
+        {"iid": "fe80::aabb:ccff:fedd:eeff", "oui": "aa:bb:cc",
+         "kind": "eui64", "first_seen": "2026-01-01T00:00:00+00:00"},
+    ])
+    row = _identity({"ipv6_link_local_iids": iids})
+    async with repo._session() as session:
+        session.add(row)
+        await session.commit()
+    async with repo._session() as session:
+        fetched = await session.get(AttackerIdentity, row.uuid)
+    assert fetched is not None
+    assert fetched.ipv6_link_local_iids == iids
+    parsed = json.loads(fetched.ipv6_link_local_iids)
+    assert parsed[0]["kind"] == "eui64"
+    assert parsed[0]["oui"] == "aa:bb:cc"
+
+
+@pytest.mark.asyncio
+async def test_identity_ipv6_iids_dedup_in_json(repo) -> None:
+    iid_val = "fe80::aabb:ccff:fedd:eeff"
+    iids = json.dumps([
+        {"iid": iid_val, "oui": "aa:bb:cc", "kind": "eui64", "first_seen": "2026-01-01T00:00:00+00:00"},
+    ])
+    row = _identity({"ipv6_link_local_iids": iids})
+    async with repo._session() as session:
+        session.add(row)
+        await session.commit()
+    async with repo._session() as session:
+        fetched = await session.get(AttackerIdentity, row.uuid)
+    existing = json.loads(fetched.ipv6_link_local_iids)
+    seen_iids = {e["iid"] for e in existing}
+    # dedup: adding same IID again should not grow the list
+    if iid_val not in seen_iids:
+        existing.append({"iid": iid_val, "oui": "aa:bb:cc", "kind": "eui64",
+                         "first_seen": "2026-01-01T00:00:00+00:00"})
+    assert len(existing) == 1
+
+
+@pytest.mark.asyncio
+async def test_existing_attacker_columns_unaffected(repo) -> None:
+    row = _attacker({"rotation_count": 5, "last_ipv6_link_local": "fe80::1"})
+    async with repo._session() as session:
+        session.add(row)
+        await session.commit()
+    async with repo._session() as session:
+        fetched = await session.get(Attacker, row.uuid)
+    assert fetched is not None
+    assert fetched.rotation_count == 5
+    assert fetched.last_ipv6_link_local == "fe80::1"