diff --git a/src/components/Markdown.svelte b/src/components/Markdown.svelte
index cc8153889..199d0ff0c 100644
--- a/src/components/Markdown.svelte
+++ b/src/components/Markdown.svelte
@@ -18,7 +18,7 @@
     canonicalize,
     isCommit,
   } from "@app/lib/utils";
-  import { Renderer, markdown } from "@app/lib/markdown";
+  import { Renderer, markdown, sanitizeConfig } from "@app/lib/markdown";
 
   export let content: string;
   export let path: string = "/";
@@ -97,7 +97,8 @@
         renderer: new Renderer($activeUnloadedRouteStore),
         breaks,
       }) as string,
-    );
+      sanitizeConfig,
+    ) as string;
   }
 
   afterUpdate(async () => {
diff --git a/src/lib/commit.ts b/src/lib/commit.ts
index 8a23f3e1c..205295939 100644
--- a/src/lib/commit.ts
+++ b/src/lib/commit.ts
@@ -142,10 +142,10 @@ export function renderCommitDescription(text: string): string {
   out += escape(trimmed.slice(cursor));
   return dompurify.sanitize(out, {
     /* eslint-disable @typescript-eslint/naming-convention */
-    ADD_TAGS: ["radicle-external-link"],
-    ADD_ATTR: ["href"],
+    ALLOWED_TAGS: ["radicle-external-link"],
+    ALLOWED_ATTR: ["href"],
     /* eslint-enable @typescript-eslint/naming-convention */
-  });
+  }) as string;
 }
 
 export async function loadRepoActivity(
diff --git a/src/lib/markdown.ts b/src/lib/markdown.ts
index c23899832..c4d0bf951 100644
--- a/src/lib/markdown.ts
+++ b/src/lib/markdown.ts
@@ -1,7 +1,7 @@
+import type { Config } from "dompurify";
 import type { MarkedExtension, Tokens } from "marked";
 import type { Route } from "@app/lib/router";
 
-import dompurify from "dompurify";
 import footnoteMarkedExtension from "marked-footnote";
 import katexMarkedExtension from "marked-katex-extension";
 import linkifyMarkedExtension from "marked-linkify-it";
@@ -12,7 +12,14 @@ import emojis from "@app/lib/emojis";
 import { canonicalize, isUrl } from "@app/lib/utils";
 import { routeToPath } from "@app/lib/router";
 
-dompurify.setConfig({
+/**
+ * DOMPurify configuration for sanitizing markdown-derived HTML. Pass this as
+ * the second argument to `dompurify.sanitize` at each call site instead of
+ * setting it globally — a global config leaks into other consumers of the
+ * DOMPurify singleton (e.g. mermaid's internal strict-mode sanitization),
+ * which would strip the SVG output of valid diagrams.
+ */
+export const sanitizeConfig: Config = {
   /* eslint-disable @typescript-eslint/naming-convention */
   ALLOWED_ATTR: [
     "align",
@@ -67,7 +74,7 @@ dompurify.setConfig({
     "ul",
   ],
   /* eslint-enable @typescript-eslint/naming-convention */
-});
+};
 
 export class Renderer extends BaseRenderer {
   #route: Route;
diff --git a/src/views/nodes/View.svelte b/src/views/nodes/View.svelte
index cae4b4eb5..f6e12c77c 100644
--- a/src/views/nodes/View.svelte
+++ b/src/views/nodes/View.svelte
@@ -2,7 +2,7 @@
   import type { BaseUrl, Node, NodeStats } from "@http-client";
 
   import dompurify from "dompurify";
-  import { markdown } from "@app/lib/markdown";
+  import { markdown, sanitizeConfig } from "@app/lib/markdown";
 
   import Command from "@app/components/Command.svelte";
   import Icon from "@app/components/Icon.svelte";
@@ -25,7 +25,8 @@
   function render(content: string): string {
     return dompurify.sanitize(
       markdown({ linkify: true, emojis: true }).parse(content) as string,
-    );
+      sanitizeConfig,
+    ) as string;
   }
 </script>
 
diff --git a/src/views/repos/Source/RepoNameHeader.svelte b/src/views/repos/Source/RepoNameHeader.svelte
index 48141f246..aaa322aa7 100644
--- a/src/views/repos/Source/RepoNameHeader.svelte
+++ b/src/views/repos/Source/RepoNameHeader.svelte
@@ -2,7 +2,7 @@
   import type { BaseUrl, Repo, SeedingPolicy } from "@http-client";
 
   import dompurify from "dompurify";
-  import { markdown } from "@app/lib/markdown";
+  import { markdown, sanitizeConfig } from "@app/lib/markdown";
   import { formatRepositoryId, twemoji } from "@app/lib/utils";
 
   import Badge from "@app/components/Badge.svelte";
@@ -19,7 +19,8 @@
   function render(content: string): string {
     return dompurify.sanitize(
       markdown({ linkify: true, emojis: true }).parseInline(content) as string,
-    );
+      sanitizeConfig,
+    ) as string;
   }
 
   $: project = repo.payloads["xyz.radicle.project"];
diff --git a/src/views/repos/components/InlineTitle.svelte b/src/views/repos/components/InlineTitle.svelte
index 04f10ceb3..ab9773e82 100644
--- a/src/views/repos/components/InlineTitle.svelte
+++ b/src/views/repos/components/InlineTitle.svelte
@@ -1,6 +1,7 @@
 <script lang="ts">
   import dompurify from "dompurify";
   import escape from "lodash/escape";
+  import { sanitizeConfig } from "@app/lib/markdown";
   import { formatInlineTitle } from "@app/lib/utils";
 
   export let content: string;
@@ -23,5 +24,5 @@
   class:txt-heading-l={fontSize === "heading-l"}
   class:txt-body-l-medium={fontSize === "body-l-medium"}
   class:txt-body-m-regular={fontSize === "body-m-regular"}>
-  {@html dompurify.sanitize(formatInlineTitle(escape(content)))}
+  {@html dompurify.sanitize(formatInlineTitle(escape(content)), sanitizeConfig)}
 </span>