diff --git a/.bot/prompts/engineer-followup/system.md b/.bot/prompts/engineer-followup/system.md
index 352ddf01..f312f633 100644
--- a/.bot/prompts/engineer-followup/system.md
+++ b/.bot/prompts/engineer-followup/system.md
@@ -18,7 +18,7 @@ Your job:
   4. End with a short summary of what changed.
 
 Repo facts you need:
-  - Go 1.25 `database/sql` driver; `go build ./...` has warmed the module cache on
+  - Go 1.27.3 `database/sql` driver; `go build ./...` has warmed the module cache on
     the runner. This follow-up job wires **NO live-warehouse connection env**, so
     only the pure-Go **`make test`** unit suite (CGO_ENABLED=0) runs here — do NOT
     run or add the live e2e tests in `driver_e2e_test.go` (they need warehouse
diff --git a/.bot/prompts/engineer-mention/system.md b/.bot/prompts/engineer-mention/system.md
index b6326448..8dcc4d04 100644
--- a/.bot/prompts/engineer-mention/system.md
+++ b/.bot/prompts/engineer-mention/system.md
@@ -18,7 +18,7 @@ the relevant source before editing. Never weaken tests or alter fixtures to
 make a check pass. Keep public API and dependency changes out of scope unless
 the maintainer explicitly requests them.
 
-The runner provides Go 1.25 and a warmed module/tool cache. Verify Go edits with
+The runner provides Go 1.27.3 and a warmed module/tool cache. Verify Go edits with
 the affected `go test -run <TestName> ./<pkg>` tests, then `make test`,
 `make lint`, and the read-only format check `gofmt -l -s .`. This job runs the
 pure-Go driver with CGO_ENABLED=0 and GOPROXY=off. It has no live-warehouse
diff --git a/.bot/prompts/engineer/system.md b/.bot/prompts/engineer/system.md
index 042c6f30..9d7703a6 100644
--- a/.bot/prompts/engineer/system.md
+++ b/.bot/prompts/engineer/system.md
@@ -11,7 +11,7 @@ prompt covers the repo-specific facts you need to follow it.
 == THE REPO ==
 
 A Go `database/sql` driver (module `github.com/databricks/databricks-sql-go`, Go
-1.25). Source is the root package `dbsql` (`connection.go`, `connector.go`,
+1.27.3). Source is the root package `dbsql` (`connection.go`, `connector.go`,
 `driver.go`, `statement.go`, `result.go`, `parameters.go`, …) plus subpackages
 `auth/`, `rows/`, `errors/`, `logger/`, `driverctx/`, `telemetry/`, and
 `internal/` (client, Thrift protocol, fetcher, etc.). Public API stability
diff --git a/.github/workflows/engineer-bot-followup.yml b/.github/workflows/engineer-bot-followup.yml
index 984b37cf..8dc8c33e 100644
--- a/.github/workflows/engineer-bot-followup.yml
+++ b/.github/workflows/engineer-bot-followup.yml
@@ -100,7 +100,7 @@ jobs:
       - name: Set up Go Toolchain
         uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16  # v6.5.0
         with:
-          go-version: '1.25.x'
+          go-version: '1.27.3'
           cache: false
 
       - name: Build + warm caches (pure-Go; while JFrog creds are present)
diff --git a/.github/workflows/engineer-bot-mention.yml b/.github/workflows/engineer-bot-mention.yml
index e8af5072..1a57f50d 100644
--- a/.github/workflows/engineer-bot-mention.yml
+++ b/.github/workflows/engineer-bot-mention.yml
@@ -103,7 +103,7 @@ jobs:
       - name: Set up Go Toolchain
         uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16  # v6.5.0
         with:
-          go-version: '1.25.x'
+          go-version: '1.27.3'
           cache: false
 
       - name: Build and warm Go caches
diff --git a/.github/workflows/engineer-bot.yml b/.github/workflows/engineer-bot.yml
index 76b8f038..f9bdb3e1 100644
--- a/.github/workflows/engineer-bot.yml
+++ b/.github/workflows/engineer-bot.yml
@@ -75,7 +75,7 @@ jobs:
       - name: Set up Go Toolchain
         uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16  # v6.5.0
         with:
-          go-version: '1.25.x'
+          go-version: '1.27.3'
           cache: false
 
       - name: Build driver + warm caches (pure-Go; while JFrog creds are present)
diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index e60f5e76..92e32bb6 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -33,28 +33,21 @@ jobs:
       - name: Set up Go Toolchain
         uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16 # v6.5.0
         with:
-          go-version: '1.25.x'
+          go-version: '1.27.3'
           cache: false
 
       - name: Lint
         uses: golangci/golangci-lint-action@db582008a42febd596419635a5abc9d9815daa9c # v9.2.1
         with:
-          # v2.x is built with go 1.25+, which is required so the
-          # linter can read Go 1.25 stdlib export data. The v1 family
-          # was built with go ≤1.23 and produces "could not import
-          # sync/atomic" typecheck errors against our `go 1.25.0`
-          # directive.
-          version: 'v2.12'
+          # Build the linter with the same Go toolchain as the driver.
+          version: 'v2.15.0'
+          install-mode: goinstall
   build-and-test:
     name: Test and Build
     strategy:
-      # Matches Go's release support window. Per go.dev/doc/devel/release,
-      # only the latest two major releases receive security patches.
-      # As of 2026-05 that's 1.25 (Active LTS) and 1.26. The protected
-      # runners pin GOTOOLCHAIN=local so we can't include 1.24 — Go would
-      # refuse to satisfy the `go 1.25.0` directive without auto-downloading.
+      # Test the minimum patched toolchain and the latest 1.27 patch.
       matrix:
-        go-version: ['1.25.x', '1.26.x']
+        go-version: ['1.27.3', '1.27.x']
     runs-on:
       group: databricks-protected-runner-group
       labels: linux-ubuntu-latest
@@ -70,6 +63,7 @@ jobs:
         uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16 # v6.5.0
         with:
           go-version: ${{ matrix.go-version }}
+          check-latest: true
           cache: false
 
       - name: Cache Go artifacts
@@ -171,7 +165,7 @@ jobs:
       - name: Set up Go Toolchain
         uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16 # v6.5.0
         with:
-          go-version: '1.25.x'
+          go-version: '1.27.3'
           cache: false
 
       # Install the exact toolchain the kernel .a is built with. rust-toolchain.toml
diff --git a/.github/workflows/nightly-e2e.yml b/.github/workflows/nightly-e2e.yml
index 569d9e86..096a0240 100644
--- a/.github/workflows/nightly-e2e.yml
+++ b/.github/workflows/nightly-e2e.yml
@@ -49,7 +49,7 @@ jobs:
       - name: Set up Go Toolchain
         uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16 # v6.5.0
         with:
-          go-version: '1.25.x'
+          go-version: '1.27.3'
           cache: false
 
       - name: Get dependencies
@@ -141,7 +141,7 @@ jobs:
       - name: Set up Go Toolchain
         uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16 # v6.5.0
         with:
-          go-version: '1.25.x'
+          go-version: '1.27.3'
           cache: false
 
       # Keep in lockstep with rust-toolchain.toml's channel (it governs the archive
diff --git a/.github/workflows/securityScan.yml b/.github/workflows/securityScan.yml
index 8aca3af7..07ebd103 100644
--- a/.github/workflows/securityScan.yml
+++ b/.github/workflows/securityScan.yml
@@ -16,13 +16,12 @@ name: Security Scan
 #
 #   - workflow_dispatch: behaves like the cron run (full reporting).
 #
-# Scanner: OSV-Scanner v2.3.8 (purl-based via OSV.dev; federates GHSA,
+# Scanner: OSV-Scanner v2.7.0 (purl-based via OSV.dev; federates GHSA,
 # NVD, Go vuln DB, RustSec, PyPA). Reads `go.mod`/`go.sum` natively --
 # no separate SBOM tool needed.
 #
 # Suppressions live in `osv-scanner.toml` as [[IgnoredVulns]] entries
-# (CVE-id global; OSV-Scanner v2.3.8 doesn't support per-package CVE
-# scoping). Each entry has a justification comment.
+# (CVE-id global). Each entry has a justification comment.
 
 on:
   pull_request:
@@ -46,9 +45,8 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
-      # JFrog OIDC + GOPROXY: skipped on fork PRs (no OIDC token from
-      # GitHub's perspective). Fork PRs still work because OSV-Scanner
-      # reads `go.mod` directly without needing to download modules.
+      # Fork PRs cannot obtain the JFrog OIDC token. Download the scanner
+      # from GitHub Releases so installation does not require GOPROXY.
       - name: Setup JFrog
         if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository
         uses: ./.github/actions/setup-jfrog
@@ -56,20 +54,15 @@ jobs:
       - name: Set up Go Toolchain
         uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
         with:
-          # Must be >= the go.mod directive (1.25.0). A floating '1.25.x'
-          # resolves to the runner's cached latest 1.25 patch, which always
-          # satisfies the 1.25.0 floor. osv-scanner shells out to
-          # govulncheck, which loads the module with this toolchain; keeping
-          # the directive at the honest 1.25.0 floor (not an inflated patch)
-          # means '1.25.x' never falls below it.
-          go-version: '1.25.x'
+          # Match the minimum patched toolchain declared in go.mod.
+          go-version: '1.27.3'
           cache: false
 
       - name: Install osv-scanner
         run: |
           set -euo pipefail
           curl -fsSL -o /tmp/osv-scanner \
-            https://github.com/google/osv-scanner/releases/download/v2.3.8/osv-scanner_linux_amd64
+            https://github.com/google/osv-scanner/releases/download/v2.7.0/osv-scanner_linux_amd64
           chmod +x /tmp/osv-scanner
           /tmp/osv-scanner --version
 
@@ -151,14 +144,10 @@ jobs:
           #   - Third-party UNKNOWN  -> BLOCKING (fail closed). A scoreless
           #     GHSA-only or MAL-* malware advisory on a dep we ship must not
           #     slip the gate.
-          #   - stdlib UNKNOWN        -> report-only (NON-blocking). These are
-          #     Go stdlib advisories flagged against the go.mod directive
-          #     floor (e.g. `go 1.25.0`); they are delivered to consumers via
-          #     GOTOOLCHAIN patch auto-download and are not a real exposure of
-          #     the module itself. Inflating the directive to the latest patch
-          #     purely to silence them would tighten the customer floor for no
-          #     security gain, so we surface them (visible in the report) but
-          #     do not block. Each finding carries `is_stdlib` for this split.
+          #   - stdlib UNKNOWN -> report-only. Findings use the go.mod floor;
+          #     actual exposure depends on the consumer's build toolchain.
+          #     Consumers must rebuild with patched Go; GOTOOLCHAIN does not
+          #     update an otherwise sufficient toolchain automatically.
           #
           # NOTE ON jq NUMBER PARSING: use `try (x|tonumber) catch null`,
           # NOT `x|tonumber?`. On a non-numeric string, `tonumber?` yields
@@ -196,8 +185,7 @@ jobs:
           TOTAL_FINDINGS=$(echo "$ALL_FINDINGS" | jq 'length')
 
           # Scoreless (UNKNOWN) findings, split by stdlib vs third-party.
-          # stdlib UNKNOWNs are report-only (delivered via GOTOOLCHAIN, not a
-          # real module exposure); third-party UNKNOWNs are blocking.
+          # stdlib UNKNOWNs are report-only; third-party UNKNOWNs are blocking.
           UNKNOWN_COUNT=$(echo "$ALL_FINDINGS" | jq '[.[] | select(.severity == "UNKNOWN")] | length')
           UNKNOWN_STDLIB_COUNT=$(echo "$ALL_FINDINGS" | jq '[.[] | select(.severity == "UNKNOWN" and .is_stdlib)] | length')
 
@@ -239,7 +227,7 @@ jobs:
             echo ""
             echo "- Total findings (any severity): \`$TOTAL_FINDINGS\`"
             echo "- Blocking findings (CVSS >= 7, or unscored non-stdlib; PR-blocking): \`$HIGH_COUNT\`"
-            echo "- Unscored/UNKNOWN findings: \`$UNKNOWN_COUNT\` total (of which \`$UNKNOWN_STDLIB_COUNT\` are stdlib — report-only, delivered via GOTOOLCHAIN)"
+            echo "- Unscored/UNKNOWN findings: \`$UNKNOWN_COUNT\` total (of which \`$UNKNOWN_STDLIB_COUNT\` are stdlib — report-only; rebuild with patched Go)"
             if [ "$TOTAL_FINDINGS" -gt 0 ]; then
               echo ""
               echo "All findings (sorted by severity desc):"
diff --git a/CHANGELOG.md b/CHANGELOG.md
index dbae70fa..61bd6c0d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Release History
 
+## Unreleased
+
+- Require Go 1.27.3 or newer to include the emSign certificate distrust fix (CVE-2026-111943).
+
 ## v1.17.0 (2026-10-20)
 - Upgrade the SQL kernel bindings to v1.2.0.
 - Add opt-in GEOMETRY / GEOGRAPHY support on the kernel backend with `WithEnableGeoSpatialSupport` or `enableGeoSpatialSupport=true`. Enabled mode returns EWKB bytes with per-row SRIDs and geo column metadata; the default remains WKT / EWKT strings. Arrow batches retain the `{srid,wkb}` struct in enabled mode.
diff --git a/Makefile b/Makefile
index 9b7327b9..07fbaa33 100644
--- a/Makefile
+++ b/Makefile
@@ -35,7 +35,7 @@ help:  ## Show this help.
 all: gen fmt lint test coverage  ## format and test everything
 
 bin/golangci-lint: go.mod go.sum
-	GOBIN=$(CURDIR)/bin go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.12.2
+	GOBIN=$(CURDIR)/bin go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.15.0
 
 bin/gotestsum: go.mod go.sum
 	@mkdir -p bin/
diff --git a/README.md b/README.md
index d59054af..3fd292f8 100644
--- a/README.md
+++ b/README.md
@@ -97,6 +97,8 @@ parameter, whether it applies to **Both**, **Thrift-only**, or **SEA-only**.
 
 ## Building
 
+Requires Go 1.27.3 or newer.
+
 The two backends differ **at build time**, not just at connect.
 
 ### Thrift (default) — pure Go, no extra step
diff --git a/go.mod b/go.mod
index 7e3779d5..34863151 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/databricks/databricks-sql-go
 
-go 1.25.0
+go 1.27.3
 
 require (
 	github.com/apache/arrow/go/v12 v12.0.1
diff --git a/internal/client/client.go b/internal/client/client.go
index fec632cd..351d1f73 100644
--- a/internal/client/client.go
+++ b/internal/client/client.go
@@ -603,7 +603,6 @@ func PooledTransport(cfg *config.Config) *http.Transport {
 		DialContext: (&net.Dialer{
 			Timeout:   30 * time.Second,
 			KeepAlive: 30 * time.Second,
-			DualStack: true,
 		}).DialContext,
 		TLSClientConfig:       tlsConfig,
 		ForceAttemptHTTP2:     true,
diff --git a/internal/errors/category_test.go b/internal/errors/category_test.go
index e2e54aba..2441c16d 100644
--- a/internal/errors/category_test.go
+++ b/internal/errors/category_test.go
@@ -60,19 +60,23 @@ func TestCategoryFromError(t *testing.T) {
 	})
 
 	t.Run("finds the tag through a fmt.Errorf %w wrapper", func(t *testing.T) {
-		inner := NewRequestError(context.TODO(), "inner", errors.New("cause")).
+		var inner error = NewRequestError(context.TODO(), "inner", errors.New("cause")).
 			WithCategory(CategoryResultSet)
 		wrapped := fmt.Errorf("outer: %w", inner)
+		assert.Same(t, inner, stderrors.Unwrap(wrapped))
+		assert.ErrorIs(t, wrapped, inner)
 		assert.Equal(t, CategoryResultSet, CategoryFromError(wrapped))
 	})
 
 	t.Run("finds the tag inside a tree-shaped chain", func(t *testing.T) {
-		inner := NewRequestError(context.TODO(), "inner", errors.New("cause")).
+		var inner error = NewRequestError(context.TODO(), "inner", errors.New("cause")).
 			WithCategory(CategoryResultSet)
 		joined := stderrors.Join(errors.New("sibling"), inner)
+		assert.ErrorIs(t, joined, inner)
 		assert.Equal(t, CategoryResultSet, CategoryFromError(joined))
 
 		multiWrap := fmt.Errorf("a: %w, b: %w", errors.New("sibling"), inner)
+		assert.ErrorIs(t, multiWrap, inner)
 		assert.Equal(t, CategoryResultSet, CategoryFromError(multiWrap))
 	})
 }
diff --git a/osv-scanner.toml b/osv-scanner.toml
index 92401615..65e06c2a 100644
--- a/osv-scanner.toml
+++ b/osv-scanner.toml
@@ -42,9 +42,7 @@ reason = "golang.org/x/crypto/openpgp not imported by this driver (verified via
 id = "GO-2026-6354"
 # CVE-2026-78662 is a denial of service in golang.org/x/crypto/ssh.
 # The driver does not import ssh: `go list -buildvcs=false -deps -test ./...`
-# resolves only golang.org/x/crypto/pbkdf2. There is no official v0.55.x
-# backport; the first fixed release (v0.56.0) requires Go 1.26 and would raise
-# the supported Go floor for code that cannot reach the vulnerable package.
+# resolves only golang.org/x/crypto/pbkdf2; the vulnerable package is unreachable.
 ignoreUntil = 2027-03-09
 reason = "golang.org/x/crypto/ssh is not imported by this driver or its tests (verified via go list -deps -test); only x/crypto/pbkdf2 is reachable. Re-review on expiry: confirm ssh remains unimported before renewing."
 
@@ -52,8 +50,6 @@ reason = "golang.org/x/crypto/ssh is not imported by this driver or its tests (v
 id = "GO-2026-6355"
 # CVE-2026-56855 is a denial of service in golang.org/x/crypto/ssh.
 # The driver does not import ssh: `go list -buildvcs=false -deps -test ./...`
-# resolves only golang.org/x/crypto/pbkdf2. There is no official v0.55.x
-# backport; the first fixed release (v0.56.0) requires Go 1.26 and would raise
-# the supported Go floor for code that cannot reach the vulnerable package.
+# resolves only golang.org/x/crypto/pbkdf2; the vulnerable package is unreachable.
 ignoreUntil = 2027-03-09
 reason = "golang.org/x/crypto/ssh is not imported by this driver or its tests (verified via go list -deps -test); only x/crypto/pbkdf2 is reachable. Re-review on expiry: confirm ssh remains unimported before renewing."