diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b4eb25deec4..1c2e7dba84b 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -45,6 +45,7 @@ workflow:
         JOB_PRIORITY: 75
         # fast-fail in merge pipelines: stop early if we get this many unexpected fails/crashes
         DEQP_RUNNER_MAX_FAILS: 40
+        S3_PROJECT_PATH: ${CI_MERGE_REQUEST_SOURCE_PROJECT_PATH}
     # Post-merge pipeline
     - if: &is-post-merge $GITLAB_USER_LOGIN == "marge-bot" && $CI_PIPELINE_SOURCE == "push"
       variables:
@@ -53,6 +54,8 @@ workflow:
         FDO_RUNNER_JOB_PRIORITY_TAG_AARCH64: priority:high-aarch64
     # Pre-merge pipeline (because merge pipelines are already caught above)
     - if: &is-merge-request $CI_PIPELINE_SOURCE == "merge_request_event"
+      variables:
+        S3_PROJECT_PATH: ${CI_MERGE_REQUEST_SOURCE_PROJECT_PATH}
     # Push to a branch on a fork
     - if: &is-push-to-fork $CI_PROJECT_NAMESPACE != "mesa" && $CI_PIPELINE_SOURCE == "push"
     # Nightly pipeline
@@ -104,8 +107,11 @@ variables:
   S3_TRACIE_PRIVATE_BUCKET: mesa-tracie-private
   # Base path used for various artifacts
   S3_BASE_PATH: "${S3_HOST}/${S3_KERNEL_BUCKET}"
+  # Since GitLab 18.2.2, the JWT subject for MRs are the target project path
+  # This can be overridden by the variables in the workflow rules
+  S3_PROJECT_PATH: ${CI_PROJECT_PATH}
   # per-pipeline artifact storage on MinIO
-  PIPELINE_ARTIFACTS_BASE: ${S3_HOST}/${S3_ARTIFACTS_BUCKET}/${CI_PROJECT_PATH}/${CI_PIPELINE_ID}
+  PIPELINE_ARTIFACTS_BASE: ${S3_HOST}/${S3_ARTIFACTS_BUCKET}/${S3_PROJECT_PATH}/${CI_PIPELINE_ID}
   # per-job artifact storage on MinIO
   JOB_ARTIFACTS_BASE: ${PIPELINE_ARTIFACTS_BASE}/${CI_JOB_ID}
   # reference images stored for traces
diff --git a/.gitlab-ci/conditional-build-image-tags.yml b/.gitlab-ci/conditional-build-image-tags.yml
index 5520a5e28eb..1d921a2df15 100644
--- a/.gitlab-ci/conditional-build-image-tags.yml
+++ b/.gitlab-ci/conditional-build-image-tags.yml
@@ -1,7 +1,7 @@
 variables:
-  CONDITIONAL_BUILD_ANDROID_CTS_TAG: b018634d732f438027ec58c0383615e7
+  CONDITIONAL_BUILD_ANDROID_CTS_TAG: b0f48de11f870c340c4c4ad4ac2b8f13
   CONDITIONAL_BUILD_ANGLE_TAG: 9aaedd74072834a3c553656b6ddc17a7
   CONDITIONAL_BUILD_CROSVM_TAG: 4079babd375b09761d59eacb25a0598a
-  CONDITIONAL_BUILD_FLUSTER_TAG: e13f8521875ebd70e207ec0f6f3d3e5b
+  CONDITIONAL_BUILD_FLUSTER_TAG: 7c6f5e2af781cd4e39358500c1549541
   CONDITIONAL_BUILD_PIGLIT_TAG: 3dec1e03175e4cca1f644435e4e479d5
-  CONDITIONAL_BUILD_VKD3D_PROTON_TAG: af0d99317a3483526f9b59eac3d88451
+  CONDITIONAL_BUILD_VKD3D_PROTON_TAG: a1ec19b34712ffc19b496abc6e3cbcc8
diff --git a/.gitlab-ci/container/baremetal_build.sh b/.gitlab-ci/container/baremetal_build.sh
index 6e368086118..02181176c87 100644
--- a/.gitlab-ci/container/baremetal_build.sh
+++ b/.gitlab-ci/container/baremetal_build.sh
@@ -12,7 +12,7 @@ S3_PATH="https://${S3_HOST}/${S3_KERNEL_BUCKET}"
 if curl -L --retry 3 -f --retry-delay 10 -s --head "${S3_PATH}/${FDO_UPSTREAM_REPO}/${LAVA_DISTRIBUTION_TAG}/lava-rootfs.tar.zst"; then
   ARTIFACTS_URL="${S3_PATH}/${FDO_UPSTREAM_REPO}/${LAVA_DISTRIBUTION_TAG}"
 else
-  ARTIFACTS_URL="${S3_PATH}/${CI_PROJECT_PATH}/${LAVA_DISTRIBUTION_TAG}"
+  ARTIFACTS_URL="${S3_PATH}/${S3_PROJECT_PATH}/${LAVA_DISTRIBUTION_TAG}"
 fi
 
 curl -L --retry 4 -f --retry-all-errors --retry-delay 60 \
diff --git a/.gitlab-ci/container/build-android-cts.sh b/.gitlab-ci/container/build-android-cts.sh
index a57227160dd..bfbe72dd5c9 100644
--- a/.gitlab-ci/container/build-android-cts.sh
+++ b/.gitlab-ci/container/build-android-cts.sh
@@ -61,7 +61,7 @@ else
     # the extraction is faster, also LAVA overlays don't support zip compression.
     tar --zstd -cf "${CTS_FILENAME}.tar.zst" /android-cts
     ci-fairy s3cp --token-file "${S3_JWT_FILE}" "${CTS_FILENAME}.tar.zst" \
-        "https://${S3_BASE_PATH}/${CI_PROJECT_PATH}/${ARTIFACT_PATH}"
+        "https://${S3_BASE_PATH}/${S3_PROJECT_PATH}/${ARTIFACT_PATH}"
 fi
 
 section_end android-cts
diff --git a/.gitlab-ci/container/build-android-x86_64-llvm.sh b/.gitlab-ci/container/build-android-x86_64-llvm.sh
index aaacc8bec40..b3c62eac9bd 100755
--- a/.gitlab-ci/container/build-android-x86_64-llvm.sh
+++ b/.gitlab-ci/container/build-android-x86_64-llvm.sh
@@ -9,7 +9,7 @@ set -exu
 
 # If CI vars are not set, assign an empty value, this prevents -u to fail
 : "${CI:=}"
-: "${CI_PROJECT_PATH:=}"
+: "${S3_PROJECT_PATH:=}"
 
 # Early check for required env variables, relies on `set -u`
 : "$ANDROID_NDK_VERSION"
@@ -26,13 +26,13 @@ if [ -n "$CI" ] && [ ! -s "${S3_JWT_FILE}" ]; then
   exit 1
 fi
 
-if curl -s -o /dev/null -I -L -f --retry 4 --retry-delay 15 "https://${S3_HOST}/${S3_ANDROID_BUCKET}/${CI_PROJECT_PATH}/${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst"; then
+if curl -s -o /dev/null -I -L -f --retry 4 --retry-delay 15 "https://${S3_HOST}/${S3_ANDROID_BUCKET}/${S3_PROJECT_PATH}/${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst"; then
   echo "Artifact ${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst already exists, skip re-building."
 
   # Download prebuilt LLVM libraries for Android when they have not changed,
   # to save some time
   curl -L --retry 4 -f --retry-all-errors --retry-delay 60 \
-    -o "/${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst" "https://${S3_HOST}/${S3_ANDROID_BUCKET}/${CI_PROJECT_PATH}/${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst"
+    -o "/${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst" "https://${S3_HOST}/${S3_ANDROID_BUCKET}/${S3_PROJECT_PATH}/${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst"
   tar -C / --zstd -xf "/${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst"
   rm "/${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst"
 
@@ -114,7 +114,7 @@ tar --zstd -cf "${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst" "$LLVM_INSTALL_PREFIX"
 # version does not change, and delete it.
 # The file is not deleted for non-CI because it can be useful in local runs.
 if [ -n "$CI" ]; then
-  ci-fairy s3cp --token-file "${S3_JWT_FILE}" "${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst" "https://${S3_HOST}/${S3_ANDROID_BUCKET}/${CI_PROJECT_PATH}/${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst"
+  ci-fairy s3cp --token-file "${S3_JWT_FILE}" "${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst" "https://${S3_HOST}/${S3_ANDROID_BUCKET}/${S3_PROJECT_PATH}/${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst"
   rm "${ANDROID_LLVM_ARTIFACT_NAME}.tar.zst"
 fi
 
diff --git a/.gitlab-ci/container/build-fluster.sh b/.gitlab-ci/container/build-fluster.sh
index 79b133450c9..ac54437770e 100644
--- a/.gitlab-ci/container/build-fluster.sh
+++ b/.gitlab-ci/container/build-fluster.sh
@@ -45,7 +45,7 @@ else
     # Build fluster vectors archive and upload it
     tar --zstd -cf "vectors.tar.zst" fluster/resources/
     ci-fairy s3cp --token-file "${S3_JWT_FILE}" "vectors.tar.zst" \
-        "https://${S3_BASE_PATH}/${CI_PROJECT_PATH}/${ARTIFACT_PATH}"
+        "https://${S3_BASE_PATH}/${S3_PROJECT_PATH}/${ARTIFACT_PATH}"
     mv fluster/ /
 fi
 
diff --git a/.gitlab-ci/container/build-vkd3d-proton.sh b/.gitlab-ci/container/build-vkd3d-proton.sh
index caf4c8f5f48..4bea5d9e4a7 100644
--- a/.gitlab-ci/container/build-vkd3d-proton.sh
+++ b/.gitlab-ci/container/build-vkd3d-proton.sh
@@ -57,7 +57,7 @@ else
   echo "Uploaded vkd3d-proton not found, reuploading..."
   tar --zstd -cf "$VKD3D_PROTON_S3_ARTIFACT" -C / "${VKD3D_PROTON_DST_DIR#/}" "${VKD3D_PROTON_WINE_DIR#/}"
   ci-fairy s3cp --token-file "${S3_JWT_FILE}" "$VKD3D_PROTON_S3_ARTIFACT" \
-    "https://${S3_BASE_PATH}/${CI_PROJECT_PATH}/${ARTIFACT_PATH}"
+    "https://${S3_BASE_PATH}/${S3_PROJECT_PATH}/${ARTIFACT_PATH}"
   rm "$VKD3D_PROTON_S3_ARTIFACT"
 fi
 
diff --git a/.gitlab-ci/container/fdo_cntr_export.sh b/.gitlab-ci/container/fdo_cntr_export.sh
index b0b04ad8775..c241393d88e 100644
--- a/.gitlab-ci/container/fdo_cntr_export.sh
+++ b/.gitlab-ci/container/fdo_cntr_export.sh
@@ -78,4 +78,4 @@ buildah rm "$container"
 curl --fail --retry-connrefused --retry 4 --retry-delay 30 \
   --header "Authorization: Bearer $(cat "${S3_JWT_FILE}")" \
   -X PUT --form file=@"$ROOTFSTAR" \
-  "https://${S3_HOST}/${S3_KERNEL_BUCKET}/${CI_PROJECT_PATH}/${CI_JOB_NAME}:${FDO_DISTRIBUTION_TAG}"
+  "https://${S3_HOST}/${S3_KERNEL_BUCKET}/${S3_PROJECT_PATH}/${CI_JOB_NAME}:${FDO_DISTRIBUTION_TAG}"
diff --git a/.gitlab-ci/image-tags.yml b/.gitlab-ci/image-tags.yml
index 6d0e827daa4..b44b24214b3 100644
--- a/.gitlab-ci/image-tags.yml
+++ b/.gitlab-ci/image-tags.yml
@@ -19,10 +19,10 @@ include:
   - .gitlab-ci/conditional-build-image-tags.yml
 
 variables:
-  DEBIAN_BUILD_BASE_TAG: "20250803-noxvfb"
+  DEBIAN_BUILD_BASE_TAG: "20250818-s3url"
   DEBIAN_BUILD_TAG: "20250722-libwayland"
 
-  DEBIAN_TEST_BASE_TAG: "20250812-crosvm"
+  DEBIAN_TEST_BASE_TAG: "20250818-s3url"
   DEBIAN_TEST_ANDROID_TAG: "20250805-vkcts"
   DEBIAN_TEST_GL_TAG: "20250805-vkcts"
   DEBIAN_TEST_VIDEO_TAG: "20250813-vector"
diff --git a/.gitlab-ci/piglit/piglit-traces.sh b/.gitlab-ci/piglit/piglit-traces.sh
index 1789b28b211..3cd885acf9d 100755
--- a/.gitlab-ci/piglit/piglit-traces.sh
+++ b/.gitlab-ci/piglit/piglit-traces.sh
@@ -106,7 +106,7 @@ replay_s3_upload_images() {
 
         __TRACE="${line%-*-*}"
         if grep -q "^$__PREFIX/$__TRACE: pass$" ".gitlab-ci/piglit/$PIGLIT_RESULTS.txt.orig"; then
-            if [ "x$CI_PROJECT_PATH" != "x$FDO_UPSTREAM_REPO" ]; then
+            if [ "x$S3_PROJECT_PATH" != "x$FDO_UPSTREAM_REPO" ]; then
                 continue
             fi
             __S3_PATH="$PIGLIT_REPLAY_REFERENCE_IMAGES_BASE"
diff --git a/.gitlab-ci/setup-test-env.sh b/.gitlab-ci/setup-test-env.sh
index 1ee8690b4bd..21a152333e0 100755
--- a/.gitlab-ci/setup-test-env.sh
+++ b/.gitlab-ci/setup-test-env.sh
@@ -300,7 +300,7 @@ function find_s3_project_artifact() {
     x_off
     local artifact_path="$1"
 
-    for project in "${FDO_UPSTREAM_REPO}" "${CI_PROJECT_PATH}"; do
+    for project in "${FDO_UPSTREAM_REPO}" "${S3_PROJECT_PATH}"; do
         local full_path="${FDO_HTTP_CACHE_URI:-}${S3_BASE_PATH}/${project}/${artifact_path}"
         if curl-with-retry -s --head "https://${full_path}" >/dev/null; then
             echo "https://${full_path}"