diff --git a/meta/recipes-connectivity/socat/files/CVE-2026-56123.patch b/meta/recipes-connectivity/socat/files/CVE-2026-56123.patch
new file mode 100644
index 00000000000..e2552a74451
--- /dev/null
+++ b/meta/recipes-connectivity/socat/files/CVE-2026-56123.patch
@@ -0,0 +1,150 @@
+From d44cd1cc4fbb70a9ae9e71890024ae8367fcb912 Mon Sep 17 00:00:00 2001
+From: Gerhard Rieger <gerhard@dest-unreach.org>
+Date: Thu, 25 Jun 2026 14:55:59 +0200
+Subject: [PATCH] Version 1.8.1.2 - fixed SOCKS5 client buffer overflow
+ (CVE-2026-56123)
+
+CVE: CVE-2026-56123
+Upstream-Status: Backport [repo.or.cz/socat.git/commitdiff/d44cd1cc4fbb70a9ae9e71890024ae8367fcb912]
+Signed-off-by: Peter Marko <peter.marko@siemens.com>
+---
+ CHANGES      | 13 ++++++++++
+ test.sh      | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++
+ xio-socks5.h |  4 +--
+ 3 files changed, 88 insertions(+), 2 deletions(-)
+
+diff --git a/CHANGES b/CHANGES
+index ba82024..3c2f230 100644
+--- a/CHANGES
++++ b/CHANGES
+@@ -1,4 +1,17 @@
+ 
++Security:
++	Socat security advisory 10
++	CVE-2026-56123
++	There was a possible heap overflow in the socks5 client code. It could
++	be triggered by connecting to a malicious socks5 server that expected
++	this connection and had knowledge about details of the client binary
++	code.
++	Only builds with C signed char (vs.unsigned char) are affected.
++	Thanks to Tristan Madani for finding and reporting this issue, and for
++	conveying the process.
++	Test: SOCKS5_OVERFL
++
++
+ ####################### V 1.8.0.0
+ 
+ Security:
+diff --git a/test.sh b/test.sh
+index 53bbb2a..467ac57 100755
+--- a/test.sh
++++ b/test.sh
+@@ -601,6 +601,9 @@ rm -rf "$TD" || (echo "cannot rm $TD" >&2; exit 1)
+ mkdir -p "$TD"
+ #trap "rm -r $TD" 0 3
+ 
++BINDIR=$td/bin
++mkdir -p $BINDIR
++
+ echo "Using temp directory $TD"
+ 
+ case "$TESTS" in
+@@ -19217,6 +19220,76 @@ fi # NUMCOND
+ esac
+ N=$((N+1))
+ 
++# Above tests introduced with 1.8.1.0 (none with 1.8.1.1)
++#==============================================================================
++# Below tests introduced with 1.8.1.2
++
++
++# Test socks5 client buffer overflow (CVE-2026-56123)
++NAME=SOCKS5_OVERFL
++case "$TESTS" in
++*%$N%*|*%functions%*|*%bugs%*|*%security%*|*%socks5%*|*%socks%*|*%%*|*%%*|*%socket%*|*%$NAME%*)
++#*%internet%*|*%root%*|*%listen%*|*%fork%*|*%ip4%*|*%tcp4%*|*%bug%*|...
++TEST="$NAME: socks5 client buffer overflow"
++# Start a listener that emulates a malicious socks5 server, using a temporary
++# shell script;
++# connect using Socat with socks5 client;
++# when is terminates with rc=0 the test succeeded (not vulnerable)
++if ! eval $NUMCOND; then :
++# Check if this test can be performed meaningfully
++elif ! cond=$(checkconds \
++		  "" \
++		  "" \
++		  "" \
++		  "IP4 TCP LISTEN SHELL GOPEN SOCKS5" \
++		  "TCP4-LISTEN SHELL GOPEN SOCKS5" \
++		  "socksport" \
++		  "tcp4" ); then
++    $PRINTF "test $F_n $TEST... ${YELLOW}$cond${NORMAL}\n" $N
++    cant
++else
++    mkdir -p "$BINDIR"
++    tf="$td/test$N.stdout"
++    te="$td/test$N.stderr"
++    tdiff="$td/test$N.diff"
++    tsh="$BINDIR/test$N.sh"
++    cat >"$tsh" <<__EOF__
++$ECHO -n "\\x05\\x00"
++relsleep 1
++$ECHO -n "\\x05\\x00\\x00\\x03\\xfdAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
++__EOF__
++    chmod a+x "$tsh"
++    newport tcp4 	# -> PORT
++    CMD0="$TRACE $SOCAT $opts TCP4-LISTEN:$PORT SHELL:$tsh"
++    CMD1="$TRACE $SOCAT $opts /dev/null SOCKS5:$LOCALHOST4:17.34.51.68:85,socksport=$PORT"
++    printf "test $F_n $TEST... " $N
++    $CMD0 >/dev/null 2>"${te}0" &
++    pid0=$!
++    waittcp4port $PORT 1
++    $CMD1 >"${tf}1" 2>"${te}1"
++    rc1=$?
++    kill $pid0 2>/dev/null; wait
++    if [ "$rc1" -ne 0 ]; then
++	$PRINTF "$FAILED (rc1=$rc1)\n"
++	echo "$CMD0 &"
++	cat "${te}0" >&2
++	echo "$CMD1"
++	cat "${te}1" >&2
++	failed
++    else
++	$PRINTF "$OK\n"
++	if [ "$VERBOSE" ]; then echo "$CMD0 &"; fi
++	if [ "$DEBUG" ];   then cat "${te}0" >&2; fi
++	if [ "$VERBOSE" ]; then echo "$CMD1"; fi
++	if [ "$DEBUG" ];   then cat "${te}1" >&2; fi
++	ok
++    fi
++fi # NUMCOND
++ ;;
++esac
++N=$((N+1))
++
++
+ # end of common tests
+ 
+ ##################################################################################
+diff --git a/xio-socks5.h b/xio-socks5.h
+index 4dab76b..d4712d2 100644
+--- a/xio-socks5.h
++++ b/xio-socks5.h
+@@ -23,7 +23,7 @@ struct socks5_request {
+ 	uint8_t command;
+ 	uint8_t reserved;
+ 	uint8_t	address_type;
+-	char	dstdata[];
++	unsigned char dstdata[];
+ };
+ 
+ struct socks5_reply {
+@@ -31,7 +31,7 @@ struct socks5_reply {
+ 	uint8_t reply;
+ 	uint8_t reserved;
+ 	uint8_t address_type;
+-	char	dstdata[];
++	unsigned char dstdata[];
+ };
+ 
+ extern const struct addrdesc xioaddr_socks5_connect;
diff --git a/meta/recipes-connectivity/socat/socat_1.8.0.0.bb b/meta/recipes-connectivity/socat/socat_1.8.0.0.bb
index bb39730005a..156fd590aee 100644
--- a/meta/recipes-connectivity/socat/socat_1.8.0.0.bb
+++ b/meta/recipes-connectivity/socat/socat_1.8.0.0.bb
@@ -12,6 +12,7 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=b234ee4d69f5fce4486a80fdaf4a4263 \
 SRC_URI = "http://www.dest-unreach.org/socat/download/socat-${PV}.tar.bz2 \
            file://0001-fix-compile-procan.c-failed.patch \
            file://CVE-2024-54661.patch \
+           file://CVE-2026-56123.patch \
 "
 
 SRC_URI[sha256sum] = "e1de683dd22ee0e3a6c6bbff269abe18ab0c9d7eb650204f125155b9005faca7"