libssh: Fix CVE-2026-59850

The stable-0.11 commit shown in [1] is the upstream fix selected for
this backport. The upstream advisory [2] documents CVE-2026-59850 and
identifies libssh 0.11.5 as the fixed release for the 0.11 series.

[1] https://git.libssh.org/projects/libssh.git/commit/?id=6edfb52b3b364577d2db0334c0514a977efceed2
[2] https://www.libssh.org/security/advisories/CVE-2026-59850.txt

Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
Signed-off-by: Anuj Mittal <anuj.mittal@oss.qualcomm.com>

meta-oe/recipes-support/libssh/libssh/CVE-2026-59850.patch

@@ -0,0 +1,40 @@
+From a207ee3b4244c0e5da902245f8b81f3617b416f3 Mon Sep 17 00:00:00 2001
+From: Jakub Jelen <jjelen@redhat.com>
+Date: Wed, 1 Jul 2026 16:43:08 +0200
+Subject: [PATCH] CVE-2026-59850 channels: Avoid processing DATA packets on
+ closed channels
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Signed-off-by: Jakub Jelen <jjelen@redhat.com>
+Reviewed-by: Pavol Žáčik <pzacik@redhat.com>
+
+CVE: CVE-2026-59850
+Upstream-Status: Backport [https://git.libssh.org/projects/libssh.git/commit/?id=6edfb52b3b364577d2db0334c0514a977efceed2]
+
+(cherry picked from commit a8a3fa352bb5213e08a35e4494c6e44360e2e38a)
+(cherry picked from commit 6edfb52b3b364577d2db0334c0514a977efceed2)
+Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
+---
+ src/channels.c | 7 +++++++
+ 1 file changed, 7 insertions(+)
+
+diff --git a/src/channels.c b/src/channels.c
+index 3afdcf11..1543c792 100644
+--- a/src/channels.c
++++ b/src/channels.c
+@@ -575,6 +575,13 @@ SSH_PACKET_CALLBACK(channel_rcv_data){
+       channel->local_window,
+       channel->remote_window);
+ 
++    if (channel->flags & SSH_CHANNEL_FLAG_CLOSED_REMOTE) {
++        SSH_LOG(SSH_LOG_WARNING, "Received data on (remotely) closed channel");
++        ssh_set_error(session, SSH_FATAL, "Received data on (remotely) closed channel");
++        SSH_STRING_FREE(str);
++        return SSH_PACKET_USED;
++    }
++
+   /* What shall we do in this case? Let's accept it anyway */
+   if (len > channel->local_window) {
+     SSH_LOG(SSH_LOG_RARE,

meta-oe/recipes-support/libssh/libssh_0.10.6.bb

@@ -40,6 +40,7 @@ SRC_URI = "git://git.libssh.org/projects/libssh.git;protocol=https;branch=stable
            file://CVE-2026-59846.patch \
            file://CVE-2026-59848.patch \
            file://CVE-2026-59848-regression.patch \
+           file://CVE-2026-59850.patch \
           "
 SRCREV = "10e09e273f69e149389b3e0e5d44b8c221c2e7f6"