diff --git a/meta-networking/recipes-support/strongswan/strongswan/CVE-2026-78135.patch b/meta-networking/recipes-support/strongswan/strongswan/CVE-2026-78135.patch
new file mode 100644
index 0000000000..1b6c472b30
--- /dev/null
+++ b/meta-networking/recipes-support/strongswan/strongswan/CVE-2026-78135.patch
@@ -0,0 +1,72 @@
+From 2c3d63bd7a05f88d25354dfe7805a5a6e474a699 Mon Sep 17 00:00:00 2001
+From: Tobias Brunner <tobias@strongswan.org>
+Date: Mon, 27 Jul 2026 08:53:50 +0200
+Subject: [PATCH] ikev2: Properly reject CREATE_CHILD_SA requests on
+ unestablished IKE_SAs
+
+The previous check was not actually enforced as long as there were still
+tasks in the passive queue (it was originally added to fix an issue on
+initiators, so the passive queue was expected to be empty).  This allowed
+an unauthenticated attacker to potentially establish a usable Child SA
+if certain preconditions were met.
+
+First, it required that the initiator is authenticated with EAP so the
+authentication and the creation of the first Child SA is deferred.
+Second, the responder must either not configure an IP address pool or
+an explicit remote TS, otherwise, traffic selector negotiation fails.
+
+Note that the half-open IKE SA and the installed IPsec SA will be removed
+after the default timeout of 30 seconds.
+
+Fixes: 8503077175cd ("ikev2: Reject CREATE_CHILD_SA exchange on unestablished IKE_SAs")
+Fixes: c60c7694d2d8 ("merged tasking branch into trunk")
+Fixes: CVE-2026-78135
+
+CVE: CVE-2026-78135
+Upstream-Status: Backport [https://github.com/strongswan/strongswan/commit/4dcb132266a954202509a3b4b3be99378f3e3b4d]
+
+Signed-off-by: Ankur Tyagi <ankur.tyagi85@gmail.com>
+---
+ src/libcharon/sa/ikev2/task_manager_v2.c | 21 +++++++++++----------
+ 1 file changed, 11 insertions(+), 10 deletions(-)
+
+diff --git a/src/libcharon/sa/ikev2/task_manager_v2.c b/src/libcharon/sa/ikev2/task_manager_v2.c
+index 5a19ce8..f9e9ab9 100644
+--- a/src/libcharon/sa/ikev2/task_manager_v2.c
++++ b/src/libcharon/sa/ikev2/task_manager_v2.c
+@@ -1134,9 +1134,18 @@ static status_t process_request(private_task_manager_t *this,
+ 	delete_payload_t *delete;
+ 	ike_sa_state_t state;
+ 
++	state = this->ike_sa->get_state(this->ike_sa);
++	if (message->get_exchange_type(message) == CREATE_CHILD_SA &&
++		(state == IKE_CREATED || state == IKE_CONNECTING))
++	{
++		DBG1(DBG_IKE, "received CREATE_CHILD_SA request for "
++			 "unestablished IKE_SA, rejected");
++		return FAILED;
++	}
++
++	/* create tasks depending on request type, if not already some queued */
+ 	if (array_count(this->passive_tasks) == 0)
+-	{	/* create tasks depending on request type, if not already some queued */
+-		state = this->ike_sa->get_state(this->ike_sa);
++	{
+ 		switch (message->get_exchange_type(message))
+ 		{
+ 			case IKE_SA_INIT:
+@@ -1177,14 +1186,6 @@ static status_t process_request(private_task_manager_t *this,
+ 			{	/* FIXME: we should prevent this on mediation connections */
+ 				bool notify_found = FALSE, ts_found = FALSE;
+ 
+-				if (state == IKE_CREATED ||
+-					state == IKE_CONNECTING)
+-				{
+-					DBG1(DBG_IKE, "received CREATE_CHILD_SA request for "
+-						 "unestablished IKE_SA, rejected");
+-					return FAILED;
+-				}
+-
+ 				enumerator = message->create_payload_enumerator(message);
+ 				while (enumerator->enumerate(enumerator, &payload))
+ 				{
diff --git a/meta-networking/recipes-support/strongswan/strongswan_6.0.6.bb b/meta-networking/recipes-support/strongswan/strongswan_6.0.6.bb
index 1597455d15..5ddc3c32b9 100644
--- a/meta-networking/recipes-support/strongswan/strongswan_6.0.6.bb
+++ b/meta-networking/recipes-support/strongswan/strongswan_6.0.6.bb
@@ -19,6 +19,7 @@ SRC_URI = "https://download.strongswan.org/strongswan-${PV}.tar.bz2 \
            file://CVE-2026-78131.patch \
            file://CVE-2026-78130.patch \
            file://CVE-2026-78132.patch \
+           file://CVE-2026-78135.patch \
 "
 
 SRC_URI[sha256sum] = "07df7cedae56a7f3bb07e66d21a1f9f87e961db70e99184e11d3819413e4f87c"