libssh2: fix CVE-2026-66032

Reference:
https://nvd.nist.gov/vuln/detail/CVE-2026-66032
5e47761465

libssh2 ptest results (qemux86-64):
  before: PASSED: 1 FAILED: 0 SKIPPED: 0
  after:  PASSED: 1 FAILED: 0 SKIPPED: 0

(From OE-Core rev: c578c63b01b919bc403b9fb27bd76a2ccc632d3c)

Signed-off-by: Jaipaul Cheernam <jaipaul.cheernam@est.tech>
Signed-off-by: Fabien Thomas <fabien.thomas@smile.fr>
Signed-off-by: Paul Barker <paul@pbarker.dev>

meta/recipes-support/libssh2/libssh2/CVE-2026-66032.patch

@@ -0,0 +1,36 @@
+From 352341aaebcf91ab16e7fcff158fef4a3b8c32f6 Mon Sep 17 00:00:00 2001
+From: Jaipaul Cheernam <jaipaul.cheernam@est.tech>
+Date: Tue, 4 Aug 2026 12:32:31 +0000
+Subject: [PATCH] Prevent dangling pointer by nullifying data (#2180)
+
+Set data to NULL after freeing it to avoid dangling pointer. fixes
+GHSA-px3w-7g75-hg7w.
+
+Credit: VladimirEliTokarev
+
+CVE: CVE-2026-66032
+Upstream-Status: Backport [https://github.com/libssh2/libssh2/commit/5e4776146552d898b9c0e1b313cd093fa8dc92d0]
+
+Backport adaptations:
+- The upstream fix uses SSH2_FREE() which was renamed from
+  LIBSSH2_FREE() in newer libssh2. Context adjusted to match
+  the 1.11.1 codebase (different line numbers and surrounding
+  function/macro names).
+
+Signed-off-by: Jaipaul Cheernam <jaipaul.cheernam@est.tech>
+---
+ src/sftp.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/src/sftp.c b/src/sftp.c
+index 6ede3111..793f267c 100644
+--- a/src/sftp.c
++++ b/src/sftp.c
+@@ -1279,6 +1279,7 @@ sftp_open(LIBSSH2_SFTP *sftp, const char *filename,
+                                "got HANDLE FXOK"));
+ 
+                 LIBSSH2_FREE(session, data);
++                data = NULL;
+ 
+                 /* silly situation, but check for a HANDLE */
+                 rc = sftp_packet_require(sftp, SSH_FXP_HANDLE,

meta/recipes-support/libssh2/libssh2_1.11.1.bb

@@ -16,6 +16,7 @@ SRC_URI = "http://www.libssh2.org/download/${BP}.tar.gz \
            file://CVE-2025-15661-1.patch \
            file://CVE-2025-15661-2.patch \
            file://CVE-2025-15661-3.patch \
+           file://CVE-2026-66032.patch \
            "
 
 SRC_URI[sha256sum] = "d9ec76cbe34db98eec3539fe2c899d26b0c837cb3eb466a56b0f109cabf658f7"