diff --git a/packages/wasm-utxo/src/zcash/mod.rs b/packages/wasm-utxo/src/zcash/mod.rs
index 3e4eaca8974..90178bfbf54 100644
--- a/packages/wasm-utxo/src/zcash/mod.rs
+++ b/packages/wasm-utxo/src/zcash/mod.rs
@@ -22,6 +22,7 @@ pub enum NetworkUpgrade {
     Nu5,
     Nu6,
     Nu6_1,
+    Nu6_2,
 }
 
 /// Parameters for a single network upgrade
@@ -43,6 +44,7 @@ impl NetworkUpgrade {
         NetworkUpgrade::Nu5,
         NetworkUpgrade::Nu6,
         NetworkUpgrade::Nu6_1,
+        NetworkUpgrade::Nu6_2,
     ];
 
     /// Get the parameters for this network upgrade
@@ -90,6 +92,16 @@ impl NetworkUpgrade {
                 mainnet_activation_height: 3146400,
                 testnet_activation_height: 3536500,
             },
+            // NU6.2: emergency hard fork re-enabling Orchard with the corrected circuit
+            // after GHSA-ghc3-g8w4-whf9. Values match ZcashFoundation/zebra
+            // `network_upgrade.rs` (CONSENSUS_BRANCH_IDS) / `constants::activation_heights`.
+            // Not yet in the pinned zebra-chain 7.0 dependency, so the parity tests below
+            // skip Nu6_2 and it is guarded by `test_nu6_2_constants` until the dep is bumped (T1-3519).
+            NetworkUpgrade::Nu6_2 => UpgradeParams {
+                branch_id: 0x5437f330,
+                mainnet_activation_height: 3364600,
+                testnet_activation_height: 4052000,
+            },
         }
     }
 
@@ -156,6 +168,22 @@ mod tests {
         }
     }
 
+    /// NU6.2 is not yet in the pinned zebra-chain dependency (see T1-3519), so it is
+    /// excluded from the parity tests below. Guard its hardcoded constants here instead.
+    /// Source: ZcashFoundation/zebra network_upgrade.rs + constants::activation_heights.
+    #[test]
+    fn test_nu6_2_constants() {
+        assert_eq!(NetworkUpgrade::Nu6_2.branch_id(), 0x5437f330);
+        assert_eq!(NetworkUpgrade::Nu6_2.mainnet_activation_height(), 3_364_600);
+        assert_eq!(NetworkUpgrade::Nu6_2.testnet_activation_height(), 4_052_000);
+        // Heights at/after activation resolve to NU6.2; the block before stays NU6.1.
+        assert_eq!(branch_id_for_height(3_364_600, true), Some(0x5437f330));
+        assert_eq!(
+            branch_id_for_height(3_364_599, true),
+            Some(NetworkUpgrade::Nu6_1.branch_id())
+        );
+    }
+
     /// Tests that verify our constants match zebra-chain crate.
     /// These tests are exhaustive - they verify ALL upgrades in zebra-chain
     /// and will fail if we're missing any.
@@ -167,9 +195,11 @@ mod tests {
         };
 
         /// Map our NetworkUpgrade to zebra-chain's NetworkUpgrade.
-        /// This match is exhaustive - if zebra adds a new upgrade, this will fail to compile.
-        fn to_zebra_upgrade(upgrade: NetworkUpgrade) -> ZebraNetworkUpgrade {
-            match upgrade {
+        /// Returns `None` for upgrades not yet present in the pinned zebra-chain
+        /// dependency (currently NU6.2 — see T1-3519). The match is otherwise exhaustive,
+        /// so a new upgrade added here without a mapping will fail to compile.
+        fn to_zebra_upgrade(upgrade: NetworkUpgrade) -> Option<ZebraNetworkUpgrade> {
+            Some(match upgrade {
                 NetworkUpgrade::Overwinter => ZebraNetworkUpgrade::Overwinter,
                 NetworkUpgrade::Sapling => ZebraNetworkUpgrade::Sapling,
                 NetworkUpgrade::Blossom => ZebraNetworkUpgrade::Blossom,
@@ -178,7 +208,9 @@ mod tests {
                 NetworkUpgrade::Nu5 => ZebraNetworkUpgrade::Nu5,
                 NetworkUpgrade::Nu6 => ZebraNetworkUpgrade::Nu6,
                 NetworkUpgrade::Nu6_1 => ZebraNetworkUpgrade::Nu6_1,
-            }
+                // NU6.2 is not in pinned zebra-chain 7.0; validated by test_nu6_2_constants.
+                NetworkUpgrade::Nu6_2 => return None,
+            })
         }
 
         /// Map zebra-chain's NetworkUpgrade to ours.
@@ -228,18 +260,21 @@ mod tests {
                     )
                 });
 
-                // Verify round-trip
+                // Verify round-trip (zebra-known upgrades always map back to Some)
                 assert_eq!(
                     to_zebra_upgrade(our_upgrade),
-                    zebra_upgrade,
+                    Some(zebra_upgrade),
                     "Round-trip failed for {:?}",
                     zebra_upgrade
                 );
             }
 
-            // Verify every upgrade in our ALL list maps to zebra
+            // Verify every upgrade in our ALL list maps to zebra.
+            // NU6.2 is not yet in the pinned zebra-chain (T1-3519), so it is skipped here.
             for &our_upgrade in NetworkUpgrade::ALL {
-                let zebra_upgrade = to_zebra_upgrade(our_upgrade);
+                let Some(zebra_upgrade) = to_zebra_upgrade(our_upgrade) else {
+                    continue;
+                };
                 assert!(
                     zebra_upgrade.branch_id().is_some(),
                     "{:?} should have a branch ID",
@@ -251,7 +286,9 @@ mod tests {
         #[test]
         fn test_branch_ids_match_zebra() {
             for &upgrade in NetworkUpgrade::ALL {
-                let zebra_upgrade = to_zebra_upgrade(upgrade);
+                let Some(zebra_upgrade) = to_zebra_upgrade(upgrade) else {
+                    continue; // NU6.2 not in pinned zebra-chain (T1-3519)
+                };
                 let expected = zebra_upgrade
                     .branch_id()
                     .map(u32::from)
@@ -272,7 +309,9 @@ mod tests {
         fn test_mainnet_heights_match_zebra() {
             let network = ZebraNetwork::Mainnet;
             for &upgrade in NetworkUpgrade::ALL {
-                let zebra_upgrade = to_zebra_upgrade(upgrade);
+                let Some(zebra_upgrade) = to_zebra_upgrade(upgrade) else {
+                    continue; // NU6.2 not in pinned zebra-chain (T1-3519)
+                };
                 let expected = zebra_upgrade
                     .activation_height(&network)
                     .map(|h| h.0)
@@ -293,7 +332,9 @@ mod tests {
         fn test_testnet_heights_match_zebra() {
             let network = ZebraNetwork::new_default_testnet();
             for &upgrade in NetworkUpgrade::ALL {
-                let zebra_upgrade = to_zebra_upgrade(upgrade);
+                let Some(zebra_upgrade) = to_zebra_upgrade(upgrade) else {
+                    continue; // NU6.2 not in pinned zebra-chain (T1-3519)
+                };
                 let expected = zebra_upgrade
                     .activation_height(&network)
                     .map(|h| h.0)