diff --git a/modules/ublog/src/main/Env.scala b/modules/ublog/src/main/Env.scala
index cb39ae71f2..e38cf300c9 100644
--- a/modules/ublog/src/main/Env.scala
+++ b/modules/ublog/src/main/Env.scala
@@ -22,6 +22,8 @@ final class Env(
     ec: scala.concurrent.ExecutionContext
 ) {
 
+  import net.{ assetBaseUrl, baseUrl }
+
   private val colls = new UblogColls(db(CollName("ublog_blog")), db(CollName("ublog_post")))
 
   val topic = wire[UblogTopicApi]
diff --git a/modules/ublog/src/main/UblogMarkup.scala b/modules/ublog/src/main/UblogMarkup.scala
index 52a338426c..5b3bd77b79 100644
--- a/modules/ublog/src/main/UblogMarkup.scala
+++ b/modules/ublog/src/main/UblogMarkup.scala
@@ -1,10 +1,12 @@
 package lila.ublog
 
 import scala.concurrent.duration._
+
 import lila.common.Chronometer
+import lila.common.config
 import lila.common.config.NetConfig
 
-final class UblogMarkup(net: NetConfig) {
+final class UblogMarkup(baseUrl: config.BaseUrl, assetBaseUrl: config.AssetBaseUrl) {
 
   private val renderer =
     new lila.common.Markdown(
@@ -21,11 +23,11 @@ final class UblogMarkup(net: NetConfig) {
   type Html = String
 
   def apply(post: UblogPost): String =
-    cache.get(post.markdown, str => postProcess(renderer(s"ublog:${post.id}")(preProcess(str))))
+    cache.get(post.markdown, str => postProcess(renderer(s"ublog:${post.id}")(preProcess(str)).pp))
 
   private def preProcess = replaceGameGifs.apply _
 
-  private def postProcess(html: String) = imageParagraph(html)
+  private def postProcess(html: String) = unescapeUnderscoreInLinks(imageParagraph(html))
 
   private val cache = lila.memo.CacheApi.scaffeineNoScheduler
     .maximumSize(2048)
@@ -33,11 +35,23 @@ final class UblogMarkup(net: NetConfig) {
 
   // replace game GIFs URLs with actual game URLs that can be embedded
   private object replaceGameGifs {
-    val regex                 = (net.assetBaseUrl + """/game/export/gif(/white|/black|)/(\w{8})\.gif""").r
-    def apply(markdown: Text) = regex.replaceAllIn(markdown, net.baseUrl.value + "/$2$1")
+    private val regex         = (assetBaseUrl.value + """/game/export/gif(/white|/black|)/(\w{8})\.gif""").r
+    def apply(markdown: Text) = regex.replaceAllIn(markdown, baseUrl.value + "/$2$1")
   }
 
   // put images into a container for styling
   private def imageParagraph(markup: Html) =
     markup.replace("""<p><img src=""", """<p class="img-container"><img src=""")
+
+  // https://github.com/ornicar/lila/issues/9767
+  // toastui editor escapes `_` as `\_` and it breaks autolinks
+  private[ublog] object unescapeUnderscoreInLinks {
+    private val hrefRegex             = """href="([^"]+)"""".r
+    private val contentRegex          = """>([^<]+)</a>""".r
+    private def unescape(txt: String) = txt.replace("""\\_""", "_")
+    def apply(markup: Html) = contentRegex.replaceAllIn(
+      hrefRegex.replaceAllIn(markup, m => s"""href="${unescape(m group 1)}""""),
+      m => s""">${unescape(m group 1)}</a>"""
+    )
+  }
 }
diff --git a/modules/ublog/src/test/UblogMarkupTest.scala b/modules/ublog/src/test/UblogMarkupTest.scala
new file mode 100644
index 0000000000..4eab66964b
--- /dev/null
+++ b/modules/ublog/src/test/UblogMarkupTest.scala
@@ -0,0 +1,33 @@
+package lila.ublog
+
+import org.specs2.execute.Result
+import org.specs2.mutable.Specification
+import scalatags.Text.all._
+
+import lila.common.config
+
+class UblogMarkupTest extends Specification {
+
+  val m = new UblogMarkup(config.BaseUrl("https://lichess.org"), config.AssetBaseUrl("https://lichess1.org"))
+
+  "backslashUnderscore" should {
+    "fix href" in {
+      m.unescapeUnderscoreInLinks(
+        """<p><a rel="nofollow noopener noreferrer" href="https://youtu.be/di6W\_i3NiJA">text</a></p>"""
+      ) must_==
+        """<p><a rel="nofollow noopener noreferrer" href="https://youtu.be/di6W_i3NiJA">text</a></p>"""
+    }
+    "fix link text" in {
+      m.unescapeUnderscoreInLinks(
+        """<p><a rel="nofollow noopener noreferrer" href="#">https://youtu.be/di6W\_i3NiJA</a></p>"""
+      ) must_==
+        """<p><a rel="nofollow noopener noreferrer" href="#">https://youtu.be/di6W_i3NiJA</a></p>"""
+    }
+    "fix href and link text" in {
+      m.unescapeUnderscoreInLinks(
+        """<p><a rel="nofollow noopener noreferrer" href="https://youtu.be/di6W\_i3NiJA">https://youtu.be/di6W\_i3NiJA</a></p>"""
+      ) must_==
+        """<p><a rel="nofollow noopener noreferrer" href="https://youtu.be/di6W_i3NiJA">https://youtu.be/di6W_i3NiJA</a></p>"""
+    }
+  }
+}