diff --git a/src/config.ts b/src/config.ts
index 6c0dd335c4..b625642c41 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -202,7 +202,10 @@ export class KubeConfig implements SecurityAuthentication {
         agentOptions.key = opts.key;
         agentOptions.pfx = opts.pfx;
         agentOptions.passphrase = opts.passphrase;
-        agentOptions.rejectUnauthorized = opts.rejectUnauthorized;
+        // Only set rejectUnauthorized if explicitly configured. When not set, fetch will use NODE_TLS_REJECT_UNAUTHORIZED env var
+        if (opts.rejectUnauthorized !== undefined) {
+            agentOptions.rejectUnauthorized = opts.rejectUnauthorized;
+        }
         // The ws docs say that it accepts anything that https.RequestOptions accepts,
         // but Typescript doesn't understand that idea (yet) probably could be fixed in
         // the typings, but for now just cast to any
@@ -259,7 +262,10 @@ export class KubeConfig implements SecurityAuthentication {
         agentOptions.key = httpsOptions.key;
         agentOptions.pfx = httpsOptions.pfx;
         agentOptions.passphrase = httpsOptions.passphrase;
-        agentOptions.rejectUnauthorized = httpsOptions.rejectUnauthorized;
+        // Only set rejectUnauthorized if explicitly configured. When not set, fetch will use NODE_TLS_REJECT_UNAUTHORIZED env var
+        if (httpsOptions.rejectUnauthorized !== undefined) {
+            agentOptions.rejectUnauthorized = httpsOptions.rejectUnauthorized;
+        }
 
         context.setAgent(this.createAgent(cluster, agentOptions));
     }
diff --git a/src/config_test.ts b/src/config_test.ts
index 96e126a09b..aab45ebbfe 100644
--- a/src/config_test.ts
+++ b/src/config_test.ts
@@ -18,7 +18,7 @@ import { fileURLToPath } from 'node:url';
 import mockfs from 'mock-fs';
 
 import { Authenticator } from './auth.js';
-import { Headers } from 'node-fetch';
+import fetch, { Headers } from 'node-fetch';
 import { HttpMethod } from './index.js';
 import { assertRequestAgentsEqual, assertRequestOptionsEqual } from './test/match-buffer.js';
 import { CoreV1Api, RequestContext } from './api.js';
@@ -27,6 +27,7 @@ import { ActionOnInvalid, Cluster, newClusters, newContexts, newUsers, User } fr
 import { ExecAuth } from './exec_auth.js';
 import { HttpProxyAgent, HttpsProxyAgent } from 'hpagent';
 import { SocksProxyAgent } from 'socks-proxy-agent';
+import { AddressInfo } from 'node:net';
 
 const kcFileName = 'testdata/kubeconfig.yaml';
 const kc2FileName = 'testdata/kubeconfig-2.yaml';
@@ -40,6 +41,9 @@ const kcInvalidContextFileName = 'testdata/empty-context-kubeconfig.yaml';
 const kcInvalidClusterFileName = 'testdata/empty-cluster-kubeconfig.yaml';
 const kcTlsServerNameFileName = 'testdata/tls-server-name-kubeconfig.yaml';
 
+const testCertFileName = 'testdata/certs/test-cert.pem';
+const testKeyFileName = 'testdata/certs/test-key.pem';
+
 const __dirname = dirname(fileURLToPath(import.meta.url));
 
 describe('Config', () => {});
@@ -491,6 +495,61 @@ describe('KubeConfig', () => {
 
             strictEqual(rc.getAgent() instanceof https.Agent, true);
         });
+
+        it('should apply NODE_TLS_REJECT_UNAUTHORIZED from environment to agent', async () => {
+            const { server, host, port } = await createTestHttpsServer((req, res) => {
+                res.setHeader('Content-Type', 'application/json');
+                if (req.url?.includes('/api/v1/namespaces')) {
+                    res.writeHead(200);
+                    res.end(
+                        JSON.stringify({
+                            apiVersion: 'v1',
+                            kind: 'NamespaceList',
+                            items: [
+                                {
+                                    apiVersion: 'v1',
+                                    kind: 'Namespace',
+                                    metadata: { name: 'default' },
+                                },
+                            ],
+                        }),
+                    );
+                } else {
+                    res.writeHead(200);
+                    res.end('ok');
+                }
+            });
+
+            const originalValue = process.env.NODE_TLS_REJECT_UNAUTHORIZED;
+            process.env.NODE_TLS_REJECT_UNAUTHORIZED = '0'; // lgtm[js/disabling-certificate-validation]
+            after(() => {
+                process.env.NODE_TLS_REJECT_UNAUTHORIZED = originalValue;
+                server.close();
+            });
+
+            const kc = new KubeConfig();
+            kc.loadFromClusterAndUser(
+                {
+                    name: 'test-cluster',
+                    server: `https://${host}:${port}`,
+                    // ignore skipTLSVerify specified from environment variables
+                } as Cluster,
+                {
+                    name: 'test-user',
+                    token: 'test-token',
+                },
+            );
+            const coreV1Api = kc.makeApiClient(CoreV1Api);
+            const namespaceList = await coreV1Api.listNamespace();
+
+            strictEqual(namespaceList.kind, 'NamespaceList');
+            strictEqual(namespaceList.items.length, 1);
+            strictEqual(namespaceList.items[0].metadata?.name, 'default');
+
+            const res2 = await fetch(`https://${host}:${port}`, await kc.applyToFetchOptions({}));
+            strictEqual(res2.status, 200);
+            strictEqual(await res2.text(), 'ok');
+        });
     });
 
     describe('loadClusterConfigObjects', () => {
@@ -1827,3 +1886,38 @@ describe('KubeConfig', () => {
         });
     });
 });
+
+// create a self-signed HTTPS test server
+async function createTestHttpsServer(
+    requestHandler?: (req: http.IncomingMessage, res: http.ServerResponse) => void,
+): Promise<{
+    server: https.Server;
+    host: string;
+    port: number;
+    ca: string;
+}> {
+    const host = 'localhost';
+
+    const cert = readFileSync(testCertFileName, 'utf8');
+    const key = readFileSync(testKeyFileName, 'utf8');
+
+    const defaultHandler = (req: http.IncomingMessage, res: http.ServerResponse) => {
+        res.writeHead(200);
+        res.end('ok');
+    };
+
+    const server = https.createServer({ key, cert }, requestHandler ?? defaultHandler);
+
+    const port = await new Promise<number>((resolve) => {
+        server.listen(0, () => {
+            resolve((server.address() as AddressInfo).port);
+        });
+    });
+
+    return {
+        server,
+        host,
+        port,
+        ca: cert, // ca is the same as cert here
+    };
+}
diff --git a/testdata/certs/test-cert.pem b/testdata/certs/test-cert.pem
new file mode 100644
index 0000000000..89591a0a25
--- /dev/null
+++ b/testdata/certs/test-cert.pem
@@ -0,0 +1,19 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/testdata/certs/test-key.pem b/testdata/certs/test-key.pem
new file mode 100644
index 0000000000..520a2a96fb
--- /dev/null
+++ b/testdata/certs/test-key.pem
@@ -0,0 +1,28 @@
+-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----