diff --git a/Cargo.toml b/Cargo.toml
index 0c184efa..39390ada 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "comrak"
-version = "0.9.0"
+version = "0.9.1"
 authors = ["Ashe Connor <ashe@kivikakk.ee>"]
 description = "A 100% CommonMark-compatible GitHub Flavored Markdown parser and formatter"
 documentation = "https://docs.rs/comrak"
diff --git a/README.md b/README.md
index 47183a34..522ce27b 100644
--- a/README.md
+++ b/README.md
@@ -43,7 +43,7 @@ curl.exe -A "MS" https://webinstall.dev/comrak | powershell
 
 ``` console
 $ comrak --help
-comrak 0.9.0
+comrak 0.9.1
 Ashe Connor <ashe@kivikakk.ee>
 A 100% CommonMark-compatible GitHub Flavored Markdown parser and formatter
 
@@ -62,14 +62,17 @@ FLAGS:
     -V, --version            Prints version information
 
 OPTIONS:
-    -c, --config-file <PATH>            Path to config file containing command-line arguments, or `none' [default:
-                                        /Users/kivikakk/.config/comrak/config]
-        --default-info-string <INFO>    Default value for fenced code block's info strings if none is given
-    -e, --extension <EXTENSION>...      Specify an extension name to use [possible values: strikethrough, tagfilter,
-                                        table, autolink, tasklist, superscript, footnotes, description-lists]
-    -t, --to <FORMAT>                   Specify output format [default: html]  [possible values: html, commonmark]
-        --header-ids <PREFIX>           Use the Comrak header IDs extension, with the given ID prefix
-        --width <WIDTH>                 Specify wrap width (0 = nowrap) [default: 0]
+    -c, --config-file <PATH>                    Path to config file containing command-line arguments, or `none'
+                                                [default: /Users/kameliya/.config/comrak/config]
+        --default-info-string <INFO>            Default value for fenced code block's info strings if none is given
+    -e, --extension <EXTENSION>...              Specify an extension name to use [possible values: strikethrough,
+                                                tagfilter, table, autolink, tasklist, superscript, footnotes,
+                                                description-lists]
+    -t, --to <FORMAT>                           Specify output format [default: html]  [possible values: html,
+                                                commonmark]
+        --front-matter-delimiter <DELIMITER>    Ignore front-matter that starts and ends with the given string
+        --header-ids <PREFIX>                   Use the Comrak header IDs extension, with the given ID prefix
+        --width <WIDTH>                         Specify wrap width (0 = nowrap) [default: 0]
 
 ARGS:
     <FILE>...    The CommonMark file to parse; or standard input if none passed
diff --git a/changelog.txt b/changelog.txt
index 311a7a14..f0428dd3 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -1,3 +1,9 @@
+### 0.9.1
+
+* SECURITY: we were matching unsafe URL prefixes, such as `data:` or
+  `javascript:`, in a case-sensitive manner.  This meant prefixes like `Data:`
+  were untouched.  Please upgrade as soon as possible.  (Kouhei Morita)
+
 ### 0.9.0
 
 * 0.8.2 was a semver-breaking change, so we're now bumping to 0.9.0.  Some