diff --git a/.github/workflows/mcp-inspector.lock.yml b/.github/workflows/mcp-inspector.lock.yml
index a6c476a93e1..ad1d4a64f61 100644
--- a/.github/workflows/mcp-inspector.lock.yml
+++ b/.github/workflows/mcp-inspector.lock.yml
@@ -996,7 +996,7 @@ jobs:
                 "url": "https://mcp.datadoghq.com/api/unstable/mcp-server/mcp?toolsets=core",
                 "headers": {
                   "DD_API_KEY": "\${DD_API_KEY}",
-                  "DD_APPLICATION_KEY": "\${DD_APP_KEY}",
+                  "DD_APPLICATION_KEY": "\${DD_APPLICATION_KEY}",
                   "DD_SITE": "\${DD_SITE}"
                 },
                 "tools": [
diff --git a/.github/workflows/smoke-otel-backends.lock.yml b/.github/workflows/smoke-otel-backends.lock.yml
index 878ea3a0c79..59f8342c061 100644
--- a/.github/workflows/smoke-otel-backends.lock.yml
+++ b/.github/workflows/smoke-otel-backends.lock.yml
@@ -769,7 +769,7 @@ jobs:
                 "url": "https://mcp.datadoghq.com/api/unstable/mcp-server/mcp?toolsets=core",
                 "headers": {
                   "DD_API_KEY": "\${DD_API_KEY}",
-                  "DD_APPLICATION_KEY": "\${DD_APP_KEY}",
+                  "DD_APPLICATION_KEY": "\${DD_APPLICATION_KEY}",
                   "DD_SITE": "\${DD_SITE}"
                 },
                 "tools": [
diff --git a/actions/setup/js/push_signed_commits.cjs b/actions/setup/js/push_signed_commits.cjs
index 31643b5d842..458c0d40c25 100644
--- a/actions/setup/js/push_signed_commits.cjs
+++ b/actions/setup/js/push_signed_commits.cjs
@@ -360,7 +360,7 @@ async function pushSignedCommits({ githubClient, owner, repo, branch, baseRef, c
         core.info(`pushSignedCommits: using chained OID from previous mutation: ${expectedHeadOid}`);
       } else {
         // First commit: check whether the branch already exists on the remote.
-        const { stdout: oidOut } = await exec.getExecOutput("git", ["ls-remote", "origin", `refs/heads/${branch}`], { cwd });
+        const { stdout: oidOut } = await exec.getExecOutput("git", ["ls-remote", "origin", `refs/heads/${branch}`], { cwd, env: { ...process.env, ...(gitAuthEnv || {}) } });
         expectedHeadOid = oidOut.trim().split(/\s+/)[0];
         if (!expectedHeadOid) {
           // Branch does not exist on the remote yet.
diff --git a/actions/setup/js/push_signed_commits.test.cjs b/actions/setup/js/push_signed_commits.test.cjs
index f07d65bd27b..dfccf271cde 100644
--- a/actions/setup/js/push_signed_commits.test.cjs
+++ b/actions/setup/js/push_signed_commits.test.cjs
@@ -730,6 +730,177 @@ describe("push_signed_commits integration tests", () => {
     });
   });
 
+  describe("git auth environment propagation", () => {
+    it("should pass gitAuthEnv to ls-remote in the signed-commit path", async () => {
+      const gitAuthEnv = {
+        GIT_CONFIG_COUNT: "1",
+        GIT_CONFIG_KEY_0: "http.https://github.com/.extraheader",
+        GIT_CONFIG_VALUE_0: "Authorization: basic test-token",
+      };
+      const sentinelKey = "PUSH_SIGNED_COMMITS_ENV_SENTINEL_1";
+      const sentinelValue = "sentinel-1";
+      const previousSentinel = process.env[sentinelKey];
+      process.env[sentinelKey] = sentinelValue;
+
+      const getExecOutput = vi.fn(async (_program, args) => {
+        if (args[0] === "rev-list") {
+          return {
+            exitCode: 0,
+            stdout: "1111111111111111111111111111111111111111 0000000000000000000000000000000000000000\n",
+            stderr: "",
+          };
+        }
+        if (args[0] === "diff-tree") {
+          return {
+            exitCode: 0,
+            stdout: ":100644 100644 0000000000000000000000000000000000000000 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa M\tmemory.json\n",
+            stderr: "",
+          };
+        }
+        if (args[0] === "ls-remote") {
+          return {
+            exitCode: 0,
+            stdout: "deadbeefdeadbeefdeadbeefdeadbeefdeadbeef\trefs/heads/auth-check-branch\n",
+            stderr: "",
+          };
+        }
+        if (args[0] === "log") {
+          return { exitCode: 0, stdout: "Auth check commit\n", stderr: "" };
+        }
+        throw new Error(`Unexpected git command: ${args.join(" ")}`);
+      });
+
+      const execProgram = vi.fn(async (_program, args, opts = {}) => {
+        if (args[0] === "cat-file" && args[1] === "blob") {
+          opts.listeners?.stdout?.(Buffer.from("memory data\n"));
+          return 0;
+        }
+        throw new Error(`Unexpected exec command: ${args.join(" ")}`);
+      });
+
+      global.exec = {
+        getExecOutput,
+        exec: execProgram,
+      };
+
+      const githubClient = makeMockGithubClient();
+
+      try {
+        await pushSignedCommits({
+          githubClient,
+          owner: "test-owner",
+          repo: "test-repo",
+          branch: "auth-check-branch",
+          baseRef: "origin/main",
+          cwd: workDir,
+          gitAuthEnv,
+        });
+      } finally {
+        if (previousSentinel === undefined) {
+          delete process.env[sentinelKey];
+        } else {
+          process.env[sentinelKey] = previousSentinel;
+        }
+      }
+
+      const lsRemoteCall = getExecOutput.mock.calls.find(call => call[1][0] === "ls-remote");
+      expect(lsRemoteCall).toBeDefined();
+      expect(lsRemoteCall[2]).toEqual(
+        expect.objectContaining({
+          cwd: workDir,
+          env: expect.objectContaining({
+            ...gitAuthEnv,
+            [sentinelKey]: sentinelValue,
+          }),
+        })
+      );
+    });
+
+    it("should include auth env on ls-remote getExecOutput git call", async () => {
+      const gitAuthEnv = {
+        GIT_CONFIG_COUNT: "1",
+        GIT_CONFIG_KEY_0: "http.https://github.com/.extraheader",
+        GIT_CONFIG_VALUE_0: "Authorization: basic test-token",
+      };
+      const sentinelKey = "PUSH_SIGNED_COMMITS_ENV_SENTINEL_2";
+      const sentinelValue = "sentinel-2";
+      const previousSentinel = process.env[sentinelKey];
+      process.env[sentinelKey] = sentinelValue;
+
+      const getExecOutput = vi.fn(async (_program, args) => {
+        if (args[0] === "rev-list") {
+          return {
+            exitCode: 0,
+            stdout: "2222222222222222222222222222222222222222 1111111111111111111111111111111111111111\n",
+            stderr: "",
+          };
+        }
+        if (args[0] === "diff-tree") {
+          return {
+            exitCode: 0,
+            stdout: ":100644 100644 0000000000000000000000000000000000000000 bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb M\tmemory.json\n",
+            stderr: "",
+          };
+        }
+        if (args[0] === "ls-remote") {
+          return {
+            exitCode: 0,
+            stdout: "cafebabecafebabecafebabecafebabecafebabe\trefs/heads/auth-check-branch\n",
+            stderr: "",
+          };
+        }
+        if (args[0] === "log") {
+          return { exitCode: 0, stdout: "Auth guard commit\n", stderr: "" };
+        }
+        throw new Error(`Unexpected git command: ${args.join(" ")}`);
+      });
+
+      global.exec = {
+        getExecOutput,
+        exec: async (_program, args, opts = {}) => {
+          if (args[0] === "cat-file" && args[1] === "blob") {
+            opts.listeners?.stdout?.(Buffer.from("memory data\n"));
+            return 0;
+          }
+          throw new Error(`Unexpected exec command: ${args.join(" ")}`);
+        },
+      };
+
+      const githubClient = makeMockGithubClient();
+
+      try {
+        await pushSignedCommits({
+          githubClient,
+          owner: "test-owner",
+          repo: "test-repo",
+          branch: "auth-check-branch",
+          baseRef: "origin/main",
+          cwd: workDir,
+          gitAuthEnv,
+        });
+      } finally {
+        if (previousSentinel === undefined) {
+          delete process.env[sentinelKey];
+        } else {
+          process.env[sentinelKey] = previousSentinel;
+        }
+      }
+
+      const networkGitCalls = getExecOutput.mock.calls.filter(call => call[1][0] === "ls-remote");
+      expect(networkGitCalls).toHaveLength(1);
+      for (const call of networkGitCalls) {
+        expect(call[2]).toEqual(
+          expect.objectContaining({
+            env: expect.objectContaining({
+              ...gitAuthEnv,
+              [sentinelKey]: sentinelValue,
+            }),
+          })
+        );
+      }
+    });
+  });
+
   // ──────────────────────────────────────────────────────
   // Commit message – multi-line body
   // ──────────────────────────────────────────────────────