diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1553bdba19..5fe956ca37 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,7 +16,7 @@ jobs:
     container:
       # Whenever the Go version is updated here, .promu.yml
       # should also be updated.
-      image: quay.io/prometheus/golang-builder:1.25-base
+      image: quay.io/prometheus/golang-builder:1.26-base
     steps:
       - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
@@ -34,7 +34,7 @@ jobs:
     name: More Go tests
     runs-on: ubuntu-latest
     container:
-      image: quay.io/prometheus/golang-builder:1.25-base
+      image: quay.io/prometheus/golang-builder:1.26-base
     steps:
       - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
@@ -55,8 +55,6 @@ jobs:
     env:
       # Enforce the Go version.
       GOTOOLCHAIN: local
-      # TODO: remove once 1.25 is the min version.
-      GOEXPERIMENT: synctest
     container:
       # The go version in this image should be N-1 wrt test_go.
       image: quay.io/prometheus/golang-builder:1.25-base
@@ -67,9 +65,6 @@ jobs:
       - run: make build
       # Don't run NPM build; don't run race-detector.
       - run: make test GO_ONLY=1 test-flags=""
-      # TODO: remove once 1.25 is the min version.
-      # ensure we can build without the tag.
-      - run: GOEXPERIMENT="" make build
 
   test_ui:
     name: UI tests
@@ -77,7 +72,7 @@ jobs:
     # Whenever the Go version is updated here, .promu.yml
     # should also be updated.
     container:
-      image: quay.io/prometheus/golang-builder:1.25-base
+      image: quay.io/prometheus/golang-builder:1.26-base
 
     steps:
       - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
@@ -104,7 +99,7 @@ jobs:
           persist-credentials: false
       - uses: actions/setup-go@4dc6199c7b1a012772edbd06daecab0f50c9053c # v6.1.0
         with:
-          go-version: 1.25.x
+          go-version: 1.26.x
       - run: |
           $TestTargets = go list ./... | Where-Object { $_ -NotMatch "(github.com/prometheus/prometheus/config|github.com/prometheus/prometheus/web)"}
           go test $TestTargets -vet=off -v
@@ -116,7 +111,7 @@ jobs:
     # Whenever the Go version is updated here, .promu.yml
     # should also be updated.
     container:
-      image: quay.io/prometheus/golang-builder:1.25-base
+      image: quay.io/prometheus/golang-builder:1.26-base
     steps:
       - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
@@ -208,7 +203,7 @@ jobs:
     name: Check generated parser
     runs-on: ubuntu-latest
     container:
-      image: quay.io/prometheus/golang-builder:1.25-base
+      image: quay.io/prometheus/golang-builder:1.26-base
     steps:
       - name: Checkout repository
         uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
@@ -231,7 +226,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@4dc6199c7b1a012772edbd06daecab0f50c9053c # v6.1.0
         with:
-          go-version: 1.25.x
+          go-version: 1.26.x
       - name: Install snmp_exporter/generator dependencies
         run: sudo apt-get update && sudo apt-get -y install libsnmp-dev
         if: github.repository == 'prometheus/snmp_exporter'
@@ -246,8 +241,7 @@ jobs:
       - name: Lint with slicelabels
         uses: golangci/golangci-lint-action@1e7e51e771db61008b38414a730f564565cf7c20 # v9.2.0
         with:
-          # goexperiment.synctest to ensure we don't miss files that depend on it.
-          args: --verbose --build-tags=slicelabels,goexperiment.synctest
+          args: --verbose --build-tags=slicelabels
           version: ${{ steps.golangci-lint-version.outputs.version }}
       - name: Lint with dedupelabels
         uses: golangci/golangci-lint-action@1e7e51e771db61008b38414a730f564565cf7c20 # v9.2.0
diff --git a/.github/workflows/fuzzing.yml b/.github/workflows/fuzzing.yml
index 55ab70dbac..579b53411e 100644
--- a/.github/workflows/fuzzing.yml
+++ b/.github/workflows/fuzzing.yml
@@ -19,7 +19,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 # v6.0.0
         with:
-          go-version: 1.25.x
+          go-version: 1.26.x
       - name: Run Fuzzing
         run: go test -fuzz=${{ matrix.fuzz_test }}$ -fuzztime=5m ./util/fuzzing
         continue-on-error: true
diff --git a/.golangci.yml b/.golangci.yml
index 8cb3265f4f..d885374fa2 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -130,6 +130,9 @@ linters:
         - omitzero
         # Disable waitgroup check until we really move to Go 1.25.
         - waitgroup
+        # Disable newexpr check for now since it introduces too many changes in our existing codebase.
+        # To be re-enabled as a part of https://github.com/prometheus/prometheus/issues/18066.
+        - newexpr
     perfsprint:
       # Optimizes even if it requires an int or uint type cast.
       int-conversion: true
diff --git a/.promu.yml b/.promu.yml
index d5205b4fdf..0e1747a62b 100644
--- a/.promu.yml
+++ b/.promu.yml
@@ -1,7 +1,7 @@
 go:
     # Whenever the Go version is updated here,
     # .github/workflows should also be updated.
-    version: 1.25
+    version: 1.26
 repository:
     path: github.com/prometheus/prometheus
 build:
diff --git a/Makefile.common b/Makefile.common
index b8c9b3844c..38a058c1e7 100644
--- a/Makefile.common
+++ b/Makefile.common
@@ -61,7 +61,7 @@ PROMU_URL     := https://github.com/prometheus/promu/releases/download/v$(PROMU_
 SKIP_GOLANGCI_LINT :=
 GOLANGCI_LINT :=
 GOLANGCI_LINT_OPTS ?=
-GOLANGCI_LINT_VERSION ?= v2.7.2
+GOLANGCI_LINT_VERSION ?= v2.9.0
 GOLANGCI_FMT_OPTS ?=
 # golangci-lint only supports linux, darwin and windows platforms on i386/amd64/arm64.
 # windows isn't included here because of the path separator being different.
diff --git a/documentation/examples/remote_storage/go.mod b/documentation/examples/remote_storage/go.mod
index 0c80c6e7c6..7f1b581598 100644
--- a/documentation/examples/remote_storage/go.mod
+++ b/documentation/examples/remote_storage/go.mod
@@ -1,6 +1,6 @@
 module github.com/prometheus/prometheus/documentation/examples/remote_storage
 
-go 1.25.5
+go 1.25.0
 
 require (
 	github.com/alecthomas/kingpin/v2 v2.4.0
@@ -64,7 +64,7 @@ require (
 	github.com/googleapis/gax-go/v2 v2.17.0 // indirect
 	github.com/gophercloud/gophercloud/v2 v2.10.0 // indirect
 	github.com/grafana/regexp v0.0.0-20250905093917-f7b3be9d1853 // indirect
-	github.com/hashicorp/consul/api v1.33.2 // indirect
+	github.com/hashicorp/consul/api v1.32.1 // indirect
 	github.com/hashicorp/go-version v1.8.0 // indirect
 	github.com/hashicorp/nomad/api v0.0.0-20260209224925-94b77491c895 // indirect
 	github.com/hetznercloud/hcloud-go/v2 v2.36.0 // indirect
diff --git a/documentation/examples/remote_storage/go.sum b/documentation/examples/remote_storage/go.sum
index 6ebede1adf..c8909ca671 100644
--- a/documentation/examples/remote_storage/go.sum
+++ b/documentation/examples/remote_storage/go.sum
@@ -184,8 +184,8 @@ github.com/gorilla/websocket v1.5.4-0.20250319132907-e064f32e3674 h1:JeSE6pjso5T
 github.com/gorilla/websocket v1.5.4-0.20250319132907-e064f32e3674/go.mod h1:r4w70xmWCQKmi1ONH4KIaBptdivuRPyosB9RmPlGEwA=
 github.com/grafana/regexp v0.0.0-20250905093917-f7b3be9d1853 h1:cLN4IBkmkYZNnk7EAJ0BHIethd+J6LqxFNw5mSiI2bM=
 github.com/grafana/regexp v0.0.0-20250905093917-f7b3be9d1853/go.mod h1:+JKpmjMGhpgPL+rXZ5nsZieVzvarn86asRlBg4uNGnk=
-github.com/hashicorp/consul/api v1.33.2 h1:Q6mE0WZsUTJerlnl9TuXzqrtZ0cKdOCsxcZhj5mKbMs=
-github.com/hashicorp/consul/api v1.33.2/go.mod h1:K3yoL/vnIBcQV/25NeMZVokRvPPERiqp2Udtr4xAfhs=
+github.com/hashicorp/consul/api v1.32.1 h1:0+osr/3t/aZNAdJX558crU3PEjVrG4x6715aZHRgceE=
+github.com/hashicorp/consul/api v1.32.1/go.mod h1:mXUWLnxftwTmDv4W3lzxYCPD199iNLLUyLfLGFJbtl4=
 github.com/hashicorp/cronexpr v1.1.3 h1:rl5IkxXN2m681EfivTlccqIryzYJSXRGRNa0xeG7NA4=
 github.com/hashicorp/cronexpr v1.1.3/go.mod h1:P4wA0KBl9C5q2hABiMO7cp6jcIg96CDh1Efb3g1PWA4=
 github.com/hashicorp/errwrap v1.1.0 h1:OxrOeh75EUXMY8TBjag2fzXGZ40LB6IKw45YeGUDY2I=
@@ -255,6 +255,8 @@ github.com/mitchellh/copystructure v1.2.0 h1:vpKXTN4ewci03Vljg/q9QvCGUDttBOGBIa1
 github.com/mitchellh/copystructure v1.2.0/go.mod h1:qLl+cE2AmVv+CoeAwDPye/v+N2HKCj9FbZEVFJRxO9s=
 github.com/mitchellh/go-homedir v1.1.0 h1:lukF9ziXFxDFPkA1vsr5zpc1XuPDn/wFntq5mG+4E0Y=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
+github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
+github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
 github.com/mitchellh/reflectwalk v1.0.2 h1:G2LzWKi524PWgd3mLHV8Y5k7s6XUvT0Gef6zxSIeXaQ=
 github.com/mitchellh/reflectwalk v1.0.2/go.mod h1:mSTlrgnPZtwu0c4WaC2kGObEpuNDbx0jmZXqmk4esnw=
 github.com/moby/docker-image-spec v1.3.1 h1:jMKff3w6PgbfSa69GfNg+zN/XLhfXJGnEx3Nl2EsFP0=
diff --git a/go.mod b/go.mod
index 89d468e874..e86caf656a 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/prometheus/prometheus
 
-go 1.25.5
+go 1.25.0
 
 require (
 	github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.0
@@ -40,7 +40,7 @@ require (
 	github.com/google/uuid v1.6.0
 	github.com/gophercloud/gophercloud/v2 v2.10.0
 	github.com/grafana/regexp v0.0.0-20250905093917-f7b3be9d1853
-	github.com/hashicorp/consul/api v1.33.2
+	github.com/hashicorp/consul/api v1.32.1
 	github.com/hashicorp/nomad/api v0.0.0-20260205205048-8315996478d1
 	github.com/hetznercloud/hcloud-go/v2 v2.36.0
 	github.com/ionos-cloud/sdk-go/v6 v6.3.6
@@ -121,6 +121,7 @@ require (
 	github.com/go-openapi/swag/stringutils v0.25.4 // indirect
 	github.com/go-openapi/swag/typeutils v0.25.4 // indirect
 	github.com/go-openapi/swag/yamlutils v0.25.4 // indirect
+	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/pb33f/jsonpath v0.7.1 // indirect
 	github.com/pb33f/ordered-map/v2 v2.3.0 // indirect
 	github.com/santhosh-tekuri/jsonschema/v6 v6.0.2 // indirect
diff --git a/go.sum b/go.sum
index bcb7b8fcc1..e723e04200 100644
--- a/go.sum
+++ b/go.sum
@@ -278,10 +278,10 @@ github.com/grafana/regexp v0.0.0-20250905093917-f7b3be9d1853 h1:cLN4IBkmkYZNnk7E
 github.com/grafana/regexp v0.0.0-20250905093917-f7b3be9d1853/go.mod h1:+JKpmjMGhpgPL+rXZ5nsZieVzvarn86asRlBg4uNGnk=
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.7 h1:X+2YciYSxvMQK0UZ7sg45ZVabVZBeBuvMkmuI2V3Fak=
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.7/go.mod h1:lW34nIZuQ8UDPdkon5fmfp2l3+ZkQ2me/+oecHYLOII=
-github.com/hashicorp/consul/api v1.33.2 h1:Q6mE0WZsUTJerlnl9TuXzqrtZ0cKdOCsxcZhj5mKbMs=
-github.com/hashicorp/consul/api v1.33.2/go.mod h1:K3yoL/vnIBcQV/25NeMZVokRvPPERiqp2Udtr4xAfhs=
-github.com/hashicorp/consul/sdk v0.17.1 h1:LumAh8larSXmXw2wvw/lK5ZALkJ2wK8VRwWMLVV5M5c=
-github.com/hashicorp/consul/sdk v0.17.1/go.mod h1:EngiixMhmw9T7wApycq6rDRFXXVUwjjf7HuLiGMH/Sw=
+github.com/hashicorp/consul/api v1.32.1 h1:0+osr/3t/aZNAdJX558crU3PEjVrG4x6715aZHRgceE=
+github.com/hashicorp/consul/api v1.32.1/go.mod h1:mXUWLnxftwTmDv4W3lzxYCPD199iNLLUyLfLGFJbtl4=
+github.com/hashicorp/consul/sdk v0.16.1 h1:V8TxTnImoPD5cj0U9Spl0TUxcytjcbbJeADFF07KdHg=
+github.com/hashicorp/consul/sdk v0.16.1/go.mod h1:fSXvwxB2hmh1FMZCNl6PwX0Q/1wdWtHJcZ7Ea5tns0s=
 github.com/hashicorp/cronexpr v1.1.3 h1:rl5IkxXN2m681EfivTlccqIryzYJSXRGRNa0xeG7NA4=
 github.com/hashicorp/cronexpr v1.1.3/go.mod h1:P4wA0KBl9C5q2hABiMO7cp6jcIg96CDh1Efb3g1PWA4=
 github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
@@ -410,6 +410,8 @@ github.com/mitchellh/copystructure v1.2.0/go.mod h1:qLl+cE2AmVv+CoeAwDPye/v+N2HK
 github.com/mitchellh/go-homedir v1.1.0 h1:lukF9ziXFxDFPkA1vsr5zpc1XuPDn/wFntq5mG+4E0Y=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
 github.com/mitchellh/mapstructure v0.0.0-20160808181253-ca63d7c062ee/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
+github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
+github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
 github.com/mitchellh/reflectwalk v1.0.2 h1:G2LzWKi524PWgd3mLHV8Y5k7s6XUvT0Gef6zxSIeXaQ=
 github.com/mitchellh/reflectwalk v1.0.2/go.mod h1:mSTlrgnPZtwu0c4WaC2kGObEpuNDbx0jmZXqmk4esnw=
 github.com/moby/docker-image-spec v1.3.1 h1:jMKff3w6PgbfSa69GfNg+zN/XLhfXJGnEx3Nl2EsFP0=
diff --git a/go.work b/go.work
index 4d53344b16..c5ba5dfad6 100644
--- a/go.work
+++ b/go.work
@@ -1,4 +1,4 @@
-go 1.25.5
+go 1.25.0
 
 use (
 	.
diff --git a/internal/tools/go.mod b/internal/tools/go.mod
index f3853a86c6..d823d637cf 100644
--- a/internal/tools/go.mod
+++ b/internal/tools/go.mod
@@ -1,6 +1,6 @@
 module github.com/prometheus/prometheus/internal/tools
 
-go 1.25.5
+go 1.25.0
 
 require (
 	github.com/bufbuild/buf v1.65.0
diff --git a/scripts/golangci-lint.yml b/scripts/golangci-lint.yml
index ae5fdc80ec..abf2529f03 100644
--- a/scripts/golangci-lint.yml
+++ b/scripts/golangci-lint.yml
@@ -30,7 +30,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@4dc6199c7b1a012772edbd06daecab0f50c9053c # v6.1.0
         with:
-          go-version: 1.25.x
+          go-version: 1.26.x
       - name: Install snmp_exporter/generator dependencies
         run: sudo apt-get update && sudo apt-get -y install libsnmp-dev
         if: github.repository == 'prometheus/snmp_exporter'
diff --git a/util/testutil/synctest/disabled.go b/util/testutil/synctest/disabled.go
deleted file mode 100644
index 595b93c650..0000000000
--- a/util/testutil/synctest/disabled.go
+++ /dev/null
@@ -1,29 +0,0 @@
-// Copyright The Prometheus Authors
-// 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.
-
-//go:build !goexperiment.synctest && !go1.25
-
-package synctest
-
-import (
-	"testing"
-)
-
-func Test(t *testing.T, _ func(t *testing.T)) {
-	t.Skip("goexperiment.synctest is not enabled")
-}
-
-func Wait() {
-	// It isn't meant to be called outside of Test().
-	panic("goexperiment.synctest is not enabled")
-}
diff --git a/util/testutil/synctest/enabled.go b/util/testutil/synctest/enabled.go
deleted file mode 100644
index d219903809..0000000000
--- a/util/testutil/synctest/enabled.go
+++ /dev/null
@@ -1,31 +0,0 @@
-// Copyright The Prometheus Authors
-// 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.
-
-//go:build goexperiment.synctest && !go1.25
-
-package synctest
-
-import (
-	"testing"
-	"testing/synctest"
-)
-
-func Test(t *testing.T, f func(t *testing.T)) {
-	synctest.Run(func() {
-		f(t)
-	})
-}
-
-func Wait() {
-	synctest.Wait()
-}
diff --git a/util/testutil/synctest/synctest.go b/util/testutil/synctest/synctest.go
index 41750f9892..e3099c2d6a 100644
--- a/util/testutil/synctest/synctest.go
+++ b/util/testutil/synctest/synctest.go
@@ -11,8 +11,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:build go1.25
-
 package synctest
 
 import (
diff --git a/web/ui/mantine-ui/src/promql/tools/go.mod b/web/ui/mantine-ui/src/promql/tools/go.mod
index 693b168206..c457864161 100644
--- a/web/ui/mantine-ui/src/promql/tools/go.mod
+++ b/web/ui/mantine-ui/src/promql/tools/go.mod
@@ -1,6 +1,6 @@
 module github.com/prometheus/prometheus/web/ui/mantine-ui/src/promql/tools
 
-go 1.25.5
+go 1.25.0
 
 require (
 	github.com/grafana/regexp v0.0.0-20250905093917-f7b3be9d1853