diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 0f8b026..7423a1b 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -8,7 +8,7 @@
 
 [versions]
 jackson = "3.2.2"
-bouncycastle = "1.85"
+bouncycastle = "1.86"
 junit-jupiter = "6.1.3"
 # pk-auth: the passkeys-first auth library set, consumed from Maven Central (NOT vendored).
 # mini-oidc depends on pk-auth-core for the passkey credential layer.