diff --git a/backend/src/app/auth/oidc.clj b/backend/src/app/auth/oidc.clj
index 93330b4e4d..7668a49b99 100644
--- a/backend/src/app/auth/oidc.clj
+++ b/backend/src/app/auth/oidc.clj
@@ -36,17 +36,6 @@
    [integrant.core :as ig]
    [yetti.response :as-alias yres]))
 
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;; HELPERS
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(defn obfuscate-string
-  [s]
-  (if (< (count s) 10)
-    (apply str (take (count s) (repeat "*")))
-    (str (subs s 0 5)
-         (apply str (take (- (count s) 5) (repeat "*"))))))
-
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; OIDC PROVIDER (GENERIC)
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -177,7 +166,7 @@
         (l/inf :hint "provider initialized"
                :provider (:id provider)
                :client-id (:client-id provider)
-               :client-secret (obfuscate-string (:client-secret provider)))
+               :client-secret (d/obfuscate-string (:client-secret provider)))
         provider)
 
       (catch Throwable cause
@@ -222,7 +211,7 @@
         (l/inf :hint "provider initialized"
                :provider (:id provider)
                :client-id (:client-id provider)
-               :client-secret (obfuscate-string (:client-secret provider)))
+               :client-secret (d/obfuscate-string (:client-secret provider)))
         provider)
 
       (catch Throwable cause
@@ -299,7 +288,7 @@
         (l/inf :hint "provider initialized"
                :provider (:id provider)
                :client-id (:client-id provider)
-               :client-secret (obfuscate-string (:client-secret provider)))
+               :client-secret (d/obfuscate-string (:client-secret provider)))
         provider)
 
       (catch Throwable cause
@@ -341,7 +330,7 @@
              :provider "gitlab"
              :base-uri (:base-uri provider)
              :client-id (:client-id provider)
-             :client-secret (obfuscate-string (:client-secret provider)))
+             :client-secret (d/obfuscate-string (:client-secret provider)))
       provider)
     (catch Throwable cause
       (ex/raise :type ::internal
@@ -361,7 +350,7 @@
         (l/inf :hint "provider initialized"
                :provider (:id provider)
                :client-id (:client-id provider)
-               :client-secret (obfuscate-string (:client-secret provider)))
+               :client-secret (d/obfuscate-string (:client-secret provider)))
         provider)
 
       (catch Throwable cause
@@ -459,7 +448,7 @@
     (l/trc :hint "fetch access token"
            :provider (:id provider)
            :client-id (:client-id provider)
-           :client-secret (obfuscate-string (:client-secret provider))
+           :client-secret (d/obfuscate-string (:client-secret provider))
            :grant-type (:grant_type params)
            :redirect-uri (:redirect_uri params))
 
@@ -512,7 +501,7 @@
   [cfg provider tdata]
   (l/trc :hint "fetch user info"
          :uri (:user-uri provider)
-         :token (obfuscate-string (:token/access tdata)))
+         :token (d/obfuscate-string (:token/access tdata)))
 
   (let [params   {:uri (:user-uri provider)
                   :headers {"Authorization" (str (:token/type tdata) " " (:token/access tdata))}
diff --git a/common/src/app/common/data.cljc b/common/src/app/common/data.cljc
index 015246c005..6f05c439da 100644
--- a/common/src/app/common/data.cljc
+++ b/common/src/app/common/data.cljc
@@ -1024,6 +1024,26 @@
       :clj
       (sort comp-fn items))))
 
+(defn obfuscate-string
+  "Obfuscates potentially sensitive values.
+
+  - One-arg arity:
+    * For strings shorter than 10 characters, all characters are replaced by `*`.
+    * For longer strings, the first 5 characters are preserved and the rest obfuscated.
+  - Two-arg arity accepts a boolean `full?` that, when true, replaces the whole value
+    by `*`, preserving only the length."
+  ([v]
+   (obfuscate-string v false))
+  ([v full?]
+   (let [s (str v)
+         n (count s)]
+     (cond
+       (zero? n) s
+       full? (apply str (repeat n "*"))
+       (< n 10) (apply str (repeat n "*"))
+       :else (str (subs s 0 5)
+                  (apply str (repeat (- n 5) "*")))))))
+
 (defn reorder
   "Reorder a vector by moving one of their items from some position to some space between positions.
    It clamps the position numbers to a valid range."
diff --git a/common/src/app/common/exceptions.cljc b/common/src/app/common/exceptions.cljc
index 6def4ef91c..8a0a9cf834 100644
--- a/common/src/app/common/exceptions.cljc
+++ b/common/src/app/common/exceptions.cljc
@@ -10,6 +10,7 @@
   (:refer-clojure :exclude [instance?])
   (:require
    #?(:clj [clojure.stacktrace :as strace])
+   [app.common.data :refer [obfuscate-string]]
    [app.common.pprint :as pp]
    [app.common.schema :as sm]
    [clojure.core :as c]
@@ -19,6 +20,10 @@
      (:import
       clojure.lang.IPersistentMap)))
 
+(def ^:private sensitive-fields
+  "Keys whose values must be obfuscated in validation explains."
+  #{:password :old-password :token :invitation-token})
+
 #?(:clj (set! *warn-on-reflection* true))
 
 (def ^:dynamic *data-length* 8)
@@ -110,7 +115,25 @@
     (explain (:explain data) opts)
 
     (contains? data ::sm/explain)
-    (sm/humanize-explain (::sm/explain data) opts)))
+    (let [exp (::sm/explain data)
+          sanitize-map (fn sanitize-map [m]
+                         (reduce-kv
+                          (fn [acc k v]
+                            (let [k* (if (string? k) (keyword k) k)]
+                              (cond
+                                (contains? sensitive-fields k*)
+                                (assoc acc k (if (map? v)
+                                               (sanitize-map v)
+                                               (obfuscate-string v true)))
+
+                                (map? v) (assoc acc k (sanitize-map v))
+                                :else (assoc acc k v))))
+                          {}
+                          m))
+          sanitize-explain (fn [exp]
+                             (cond-> exp
+                               (:value exp) (update :value sanitize-map)))]
+      (sm/humanize-explain (sanitize-explain exp) opts))))
 
 #?(:clj
    (defn format-throwable