diff --git a/docs-site/extensions/antora-static-nav/lib/index.js b/docs-site/extensions/antora-static-nav/lib/index.js
index 67ff93c58..32ac8e4bc 100644
--- a/docs-site/extensions/antora-static-nav/lib/index.js
+++ b/docs-site/extensions/antora-static-nav/lib/index.js
@@ -87,6 +87,44 @@ function cleanNav (nav) {
     .replace(/(<li\b[^>]+class=["'][^"']*?)\s+is-active\b/g, '$1')
 }
 
+// ---------------------------------------------------------------------------
+// Href/src rebasing
+// ---------------------------------------------------------------------------
+
+const URL_REBASE_RX = /(\s(?:href|src)=)(["'])([^"']*)\2/g
+const ABSOLUTE_OR_FRAGMENT_RX = /^(?:[a-z][a-z0-9+.-]*:|\/\/|\/|#|data:|mailto:)/i
+
+/**
+ * Rewrite a single href/src value so it is relative to the component@version
+ * root rather than to the sample page's directory.
+ *
+ * Antora emits nav URLs as page-relative paths. When the captured nav is
+ * reused on pages at a different depth, these page-relative paths break.
+ * Normalising to component-root-relative makes the URLs portable; the loader
+ * then prepends each page's own back-to-root prefix at injection time.
+ */
+function rebaseUrl (value, sampleDirRelToRoot) {
+  if (!value) return value
+  if (ABSOLUTE_OR_FRAGMENT_RX.test(value)) return value
+  const base = sampleDirRelToRoot ? '/' + sampleDirRelToRoot + '/' : '/'
+  const resolved = path.posix.normalize(base + value)
+  return resolved.replace(/^\/+/, '')
+}
+
+/**
+ * Rebase every href/src in the nav HTML to be component-root-relative.
+ * `sampleDirRelToRoot` is the sample page's directory expressed relative to
+ * the component@version output root (e.g. "" for a root-level page,
+ * "source" for source/foo.html, "module/sub" for nested pages).
+ */
+function rebaseNav (navHtml, sampleDirRelToRoot) {
+  const norm = sampleDirRelToRoot && sampleDirRelToRoot !== '.' ? sampleDirRelToRoot : ''
+  return navHtml.replace(URL_REBASE_RX, (m, attr, q, val) => {
+    const next = rebaseUrl(val, norm)
+    return next === val ? m : `${attr}${q}${next}${q}`
+  })
+}
+
 // ---------------------------------------------------------------------------
 // Output builders
 // ---------------------------------------------------------------------------
@@ -94,19 +132,27 @@ function cleanNav (nav) {
 /**
  * Build the content of _static_nav.js.
  *
- * Injects the nav synchronously via currentScript.parentNode.insertBefore —
- * no document.write(), no fetch(). JSON.stringify handles all HTML escaping.
+ * Exposes window.__antoraStaticNav(prefix). The per-page inline script calls
+ * it with the page's relative path back to the component@version root, so a
+ * single shared nav can serve pages at any depth. The injected nav is placed
+ * just before the calling script, where the original nav block lived.
  */
 function buildNavJs (navHtml) {
   const navJson = JSON.stringify(navHtml)
   return (
-    '(function(){' +
-    'var s=document.currentScript||document.scripts[document.scripts.length-1];' +
+    'window.__antoraStaticNav=function(prefix){' +
+    'var s=document.currentScript;' +
+    'if(!s){var ss=document.scripts;s=ss[ss.length-1];}' +
+    'if(!s)return;' +
+    `var html=${navJson};` +
+    'if(prefix){html=html.replace(/(\\s(?:href|src)=)(["\'])([^"\']*)\\2/g,function(m,a,q,v){' +
+    'if(/^(?:[a-z][a-z0-9+.-]*:|\\/\\/|\\/|#|data:|mailto:)/i.test(v))return m;' +
+    'return a+q+prefix+v+q;});}' +
     'var t=document.createElement("div");' +
-    `t.innerHTML=${navJson};` +
+    't.innerHTML=html;' +
     'var n=t.firstChild;' +
     'if(n)s.parentNode.insertBefore(n,s);' +
-    '})();\n'
+    '};\n'
   )
 }
 
@@ -114,12 +160,15 @@ function buildNavJs (navHtml) {
  * Build the HTML fragment that replaces a page's embedded nav block.
  *
  * Two <script> elements:
- *   1. Synchronous loader — injects _static_nav.js before site.js runs
- *   2. Tiny inline — re-applies is-current-page to this page's nav entry
+ *   1. Synchronous loader — fetches _static_nav.js (defines the global)
+ *   2. Tiny inline — invokes the global with this page's back-to-root prefix
+ *      and re-applies is-current-page to this page's nav entry
  */
-function buildReplacement (navRel, pageBasename) {
+function buildReplacement (navRel, pageBasename, prefix) {
   const fileJson = JSON.stringify(pageBasename)
+  const prefixJson = JSON.stringify(prefix || '')
   const currentPageJs =
+    `window.__antoraStaticNav&&window.__antoraStaticNav(${prefixJson});` +
     `!function(){var f=${fileJson},` +
     "ls=document.querySelectorAll('.nav-link[href]');" +
     'for(var i=0;i<ls.length;i++){' +
@@ -134,7 +183,16 @@ function buildReplacement (navRel, pageBasename) {
 // Extension entry point
 // ---------------------------------------------------------------------------
 
-module.exports = { findNavBlock, cleanNav, buildNavJs, buildReplacement, MARKER, SHARED_NAV_NAME }
+module.exports = {
+  findNavBlock,
+  cleanNav,
+  rebaseNav,
+  rebaseUrl,
+  buildNavJs,
+  buildReplacement,
+  MARKER,
+  SHARED_NAV_NAME,
+}
 
 module.exports.register = function register ({ config = {} }) {
   const threshold = config.threshold ?? 50_000
@@ -160,13 +218,20 @@ module.exports.register = function register ({ config = {} }) {
     let totalSaved = 0
 
     for (const [key, pages] of groups) {
+      const { component, version } = pages[0].src
+      const componentRoot = path.posix.join(component, version)
+
       // Sample up to 10 pages to find the first one with a large-enough nav.
+      // Capture the sample's directory so we can rebase nav URLs to be
+      // relative to the component@version root.
       let navHtml = null
       for (const page of pages.slice(0, 10)) {
         const html = page.contents.toString('utf8')
         const block = findNavBlock(html)
         if (block && block.text.length >= threshold) {
-          navHtml = cleanNav(block.text)
+          const sampleDir = page.out.dirname.replace(/\\/g, '/')
+          const sampleDirRelToRoot = path.posix.relative(componentRoot, sampleDir)
+          navHtml = rebaseNav(cleanNav(block.text), sampleDirRelToRoot)
           break
         }
       }
@@ -179,8 +244,7 @@ module.exports.register = function register ({ config = {} }) {
         'static-nav: extracting shared nav'
       )
 
-      const { component, version } = pages[0].src
-      const navJsOutPath = path.join(component, version, SHARED_NAV_NAME).replace(/\\/g, '/')
+      const navJsOutPath = path.posix.join(componentRoot, SHARED_NAV_NAME)
 
       const navJsContent = buildNavJs(navHtml)
       siteCatalog.addFile({
@@ -208,11 +272,15 @@ module.exports.register = function register ({ config = {} }) {
           continue
         }
 
-        const navRel = path
-          .relative(page.out.dirname, navJsOutPath)
-          .replace(/\\/g, '/')
+        const pageDir = page.out.dirname.replace(/\\/g, '/')
+        const navRel = path.posix.relative(pageDir, navJsOutPath)
+        // Per-page prefix taking nav URLs from component-root-relative back
+        // to the URL space of this page (e.g. "" for root pages, "../" for
+        // pages one level deep, "../../" for two levels, etc.).
+        const backToRoot = path.posix.relative(pageDir, componentRoot)
+        const prefix = backToRoot === '' ? '' : backToRoot + '/'
 
-        const replacement = buildReplacement(navRel, page.out.basename)
+        const replacement = buildReplacement(navRel, page.out.basename, prefix)
         const newHtml = html.slice(0, block.start) + replacement + html.slice(block.end)
         page.contents = Buffer.from(newHtml, 'utf8')
 
diff --git a/docs-site/extensions/antora-static-nav/test/integration.test.js b/docs-site/extensions/antora-static-nav/test/integration.test.js
index 3eba3627f..1c5269b2a 100644
--- a/docs-site/extensions/antora-static-nav/test/integration.test.js
+++ b/docs-site/extensions/antora-static-nav/test/integration.test.js
@@ -166,4 +166,93 @@ describe('register integration', () => {
     const rewritten = page.contents.toString('utf8')
     assert.ok(rewritten.includes('"vkSpecialFn.html"'), 'page filename in inline script')
   })
+
+  // Regression for the /source/source/ duplication bug. When the nav is
+  // sampled from one page and reused on pages at a different depth, the
+  // shared nav HTML must use component-root-relative URLs and each page's
+  // loader call must pass the right back-to-root prefix so the browser
+  // resolves the link against the page correctly.
+  it('serves correct links across pages at different depths', () => {
+    // Build a realistic nav with hrefs pointing into source/.
+    const navWithRealLinks =
+      '<div id="split-0"><ul class="nav-list">' +
+      '<li class="nav-item"><a class="nav-link" href="source/VK_AMDX_dense_geometry_format.html">Ext</a></li>' +
+      '<li class="nav-item"><a class="nav-link" href="index.html">Home</a></li>' +
+      '<li>' + 'x'.repeat(60_000) + '</li>' +
+      '</ul></div>'
+
+    // Two pages: one at component root, one nested under source/.
+    const rootPage = makePage('spec', 'latest', 'ROOT', 'index.html', navWithRealLinks)
+    const sourcePage = makePage('spec', 'latest', 'ROOT', 'VK_AMDX_other.html', navWithRealLinks)
+    // Hack: rewrite the source page's out path so it lives in source/.
+    sourcePage.out.dirname = 'spec/latest/source'
+    sourcePage.out.path = 'spec/latest/source/VK_AMDX_other.html'
+
+    const ctx = makeContext([rootPage, sourcePage])
+    ctx.fire('pagesComposed')
+
+    const navFile = ctx._addedFiles[0]
+    const navJs = navFile.contents.toString('utf8')
+
+    // The root page samples first (Map iteration is insertion order). Sample
+    // dir is "" so the nav HTML is preserved; the link to source/ext stays
+    // "source/VK_AMDX_dense_geometry_format.html" in the shared nav.
+    assert.ok(
+      navJs.includes('source/VK_AMDX_dense_geometry_format.html'),
+      'shared nav contains the component-root-relative link'
+    )
+
+    // The root page should call the global with an empty prefix; resolving
+    // "source/foo.html" from spec/latest/index.html yields the correct URL.
+    const rootHtml = rootPage.contents.toString('utf8')
+    assert.ok(
+      rootHtml.includes('window.__antoraStaticNav&&window.__antoraStaticNav("")'),
+      `root page expected empty prefix, got: ${rootHtml.match(/__antoraStaticNav\([^)]*\)/g)}`
+    )
+
+    // The source page must call with prefix "../" so the browser resolves
+    // "../source/VK_AMDX_dense_geometry_format.html" relative to
+    // spec/latest/source/ → spec/latest/source/VK_AMDX_dense_geometry_format.html
+    // — NOT spec/latest/source/source/VK_AMDX_dense_geometry_format.html.
+    const sourceHtml = sourcePage.contents.toString('utf8')
+    assert.ok(
+      sourceHtml.includes('window.__antoraStaticNav&&window.__antoraStaticNav("../")'),
+      `source page expected "../" prefix, got: ${sourceHtml.match(/__antoraStaticNav\([^)]*\)/g)}`
+    )
+  })
+
+  // Same scenario, but the sample is taken from a nested page first. The
+  // captured nav has page-relative hrefs; rebasing must promote them to
+  // component-root-relative so the empty-prefix root page still works.
+  it('rebases captured nav when the sample page is nested', () => {
+    const navWithRealLinks =
+      '<div id="split-0"><ul class="nav-list">' +
+      // From a page in source/, a sibling extension is just a basename.
+      '<li class="nav-item"><a class="nav-link" href="VK_AMDX_dense_geometry_format.html">Ext</a></li>' +
+      // From a page in source/, the component root index is "../index.html".
+      '<li class="nav-item"><a class="nav-link" href="../index.html">Home</a></li>' +
+      '<li>' + 'x'.repeat(60_000) + '</li>' +
+      '</ul></div>'
+
+    const sourcePage = makePage('spec', 'latest', 'ROOT', 'VK_AMDX_other.html', navWithRealLinks)
+    sourcePage.out.dirname = 'spec/latest/source'
+    sourcePage.out.path = 'spec/latest/source/VK_AMDX_other.html'
+    const rootPage = makePage('spec', 'latest', 'ROOT', 'index.html', navWithRealLinks)
+
+    // Insert source page first so it's the sample.
+    const ctx = makeContext([sourcePage, rootPage])
+    ctx.fire('pagesComposed')
+
+    const navJs = ctx._addedFiles[0].contents.toString('utf8')
+    // After rebasing from sample dir "source": the basename href becomes
+    // "source/VK_AMDX_..." and "../index.html" becomes "index.html".
+    // Hrefs live inside a JSON-encoded HTML string, so the surrounding
+    // quotes are escaped (\").
+    assert.ok(navJs.includes('source/VK_AMDX_dense_geometry_format.html'),
+      'sibling href was rebased into source/')
+    assert.ok(navJs.includes('href=\\"index.html\\"'),
+      'parent-relative href was collapsed to component-root index.html')
+    assert.ok(!navJs.includes('href=\\"../index.html\\"'),
+      'rebased nav must not retain the original ../index.html')
+  })
 })
diff --git a/docs-site/extensions/antora-static-nav/test/unit.test.js b/docs-site/extensions/antora-static-nav/test/unit.test.js
index 519cba135..290218f02 100644
--- a/docs-site/extensions/antora-static-nav/test/unit.test.js
+++ b/docs-site/extensions/antora-static-nav/test/unit.test.js
@@ -5,7 +5,16 @@
 const { describe, it } = require('node:test')
 const assert = require('node:assert/strict')
 
-const { findNavBlock, cleanNav, buildNavJs, buildReplacement, MARKER, SHARED_NAV_NAME } = require('../lib/index.js')
+const {
+  findNavBlock,
+  cleanNav,
+  rebaseNav,
+  rebaseUrl,
+  buildNavJs,
+  buildReplacement,
+  MARKER,
+  SHARED_NAV_NAME,
+} = require('../lib/index.js')
 
 // ---------------------------------------------------------------------------
 // findNavBlock
@@ -97,15 +106,88 @@ describe('cleanNav', () => {
   })
 })
 
+// ---------------------------------------------------------------------------
+// rebaseUrl
+// ---------------------------------------------------------------------------
+
+describe('rebaseUrl', () => {
+  it('returns absolute URLs unchanged', () => {
+    assert.equal(rebaseUrl('https://example.com/x', 'source'), 'https://example.com/x')
+    assert.equal(rebaseUrl('//cdn/x', 'source'), '//cdn/x')
+    assert.equal(rebaseUrl('/already/absolute.html', 'source'), '/already/absolute.html')
+    assert.equal(rebaseUrl('mailto:a@b.c', 'source'), 'mailto:a@b.c')
+    assert.equal(rebaseUrl('data:image/png;base64,xx', 'source'), 'data:image/png;base64,xx')
+  })
+
+  it('returns fragment-only URLs unchanged', () => {
+    assert.equal(rebaseUrl('#section', 'source'), '#section')
+  })
+
+  it('returns the value unchanged when sample is at the component root', () => {
+    assert.equal(rebaseUrl('source/foo.html', ''), 'source/foo.html')
+    assert.equal(rebaseUrl('source/foo.html', '.'), 'source/foo.html')
+  })
+
+  it('prefixes a sibling-relative href with the sample directory', () => {
+    // Sample lives in source/, href is sibling — rebased value points into source/.
+    assert.equal(rebaseUrl('VK_AMDX_dense_geometry_format.html', 'source'),
+      'source/VK_AMDX_dense_geometry_format.html')
+  })
+
+  it('resolves leading ../ against the sample directory', () => {
+    assert.equal(rebaseUrl('../proposals/foo.html', 'source'), 'proposals/foo.html')
+  })
+
+  it('handles deeper sample directories', () => {
+    assert.equal(rebaseUrl('foo.html', 'module/sub'), 'module/sub/foo.html')
+    assert.equal(rebaseUrl('../bar.html', 'module/sub'), 'module/bar.html')
+    assert.equal(rebaseUrl('../../top.html', 'module/sub'), 'top.html')
+  })
+})
+
+// ---------------------------------------------------------------------------
+// rebaseNav
+// ---------------------------------------------------------------------------
+
+describe('rebaseNav', () => {
+  it('rewrites href values to be component-root-relative', () => {
+    const nav = '<a href="VK_AMDX_dense_geometry_format.html">x</a>'
+    const out = rebaseNav(nav, 'source')
+    assert.ok(out.includes('href="source/VK_AMDX_dense_geometry_format.html"'))
+  })
+
+  it('rewrites src values too', () => {
+    const nav = '<img src="icon.png">'
+    assert.ok(rebaseNav(nav, 'source').includes('src="source/icon.png"'))
+  })
+
+  it('leaves nav unchanged when sample is at the component root', () => {
+    const nav = '<a href="source/foo.html">f</a><a href="bar.html">b</a>'
+    assert.equal(rebaseNav(nav, ''), nav)
+  })
+
+  it('preserves absolute and fragment URLs', () => {
+    const nav = '<a href="https://x/y">x</a><a href="#anchor">y</a><a href="/abs.html">z</a>'
+    assert.equal(rebaseNav(nav, 'source'), nav)
+  })
+
+  it('handles multiple links in one nav', () => {
+    const nav = '<a href="a.html">A</a><a href="b.html">B</a>'
+    const out = rebaseNav(nav, 'source')
+    assert.ok(out.includes('href="source/a.html"'))
+    assert.ok(out.includes('href="source/b.html"'))
+  })
+})
+
 // ---------------------------------------------------------------------------
 // buildNavJs
 // ---------------------------------------------------------------------------
 
 describe('buildNavJs', () => {
-  it('produces a self-invoking function string', () => {
+  it('exposes a global function instead of running immediately', () => {
     const js = buildNavJs('<div id="split-0">nav</div>')
-    assert.ok(js.startsWith('(function(){'))
-    assert.ok(js.endsWith('})();\n'))
+    assert.ok(js.startsWith('window.__antoraStaticNav=function(prefix){'))
+    assert.ok(js.endsWith('};\n'))
   })
 
   it('JSON-encodes the nav HTML inside the JS', () => {
@@ -119,6 +201,13 @@ describe('buildNavJs', () => {
     assert.ok(js.includes('insertBefore'))
     assert.ok(!js.includes('document.write'))
   })
+
+  it('contains runtime href-prefix logic', () => {
+    const js = buildNavJs('<div></div>')
+    assert.ok(js.includes('prefix'))
+    // The runtime regex should match the same attributes the build-time one does.
+    assert.ok(js.includes('href|src'))
+  })
 })
 
 // ---------------------------------------------------------------------------
@@ -127,23 +216,34 @@ describe('buildNavJs', () => {
 
 describe('buildReplacement', () => {
   it('starts with the marker comment', () => {
-    const r = buildReplacement('../_static_nav.js', 'vkFoo.html')
+    const r = buildReplacement('../_static_nav.js', 'vkFoo.html', '../')
     assert.ok(r.startsWith(MARKER))
   })
 
   it('includes a script tag loading the shared nav JS', () => {
-    const r = buildReplacement('../_static_nav.js', 'vkFoo.html')
+    const r = buildReplacement('../_static_nav.js', 'vkFoo.html', '../')
     assert.ok(r.includes('<script src="../_static_nav.js">'))
   })
 
+  it('invokes the static-nav global with the per-page prefix', () => {
+    const r = buildReplacement('../_static_nav.js', 'vkFoo.html', '../')
+    assert.ok(r.includes('window.__antoraStaticNav'))
+    assert.ok(r.includes('"../"'))
+  })
+
+  it('passes an empty prefix for pages at the component root', () => {
+    const r = buildReplacement('_static_nav.js', 'index.html', '')
+    assert.ok(r.includes('window.__antoraStaticNav&&window.__antoraStaticNav("")'))
+  })
+
   it('includes an inline script referencing the page filename', () => {
-    const r = buildReplacement('../_static_nav.js', 'vkFoo.html')
+    const r = buildReplacement('../_static_nav.js', 'vkFoo.html', '../')
     assert.ok(r.includes('"vkFoo.html"'))
     assert.ok(r.includes('is-current-page'))
   })
 
   it('uses the navRel path verbatim in the src attribute', () => {
-    const r = buildReplacement('../../spec/latest/_static_nav.js', 'index.html')
+    const r = buildReplacement('../../spec/latest/_static_nav.js', 'index.html', '../../')
     assert.ok(r.includes('src="../../spec/latest/_static_nav.js"'))
   })
 })