new file mode 100644
@@ -0,0 +1,389 @@
+From 955e8ba9821afde4a7ac22caef794dfffe5b4b5f Mon Sep 17 00:00:00 2001
+From: Daniel Stenberg <daniel@haxx.se>
+Date: Fri, 5 Jun 2026 01:22:37 -0700
+Subject: [PATCH] setopt: clear proxy auth properties when switching
+
+Verify with test 1588
+
+Closes #21453
+
+CVE: CVE-2026-7168
+Upstream-Status: Backport [https://github.com/curl/curl/commit/c1cfdf59acbaf9504c4578d4cf56cdd7c8594507]
+
+Backport Changes:
+- curl-8.7.1 does not expose Curl_auth_digest_cleanup() to setopt.c in the
+ same way as the newer upstream tree. This backport therefore adds the
+ vauth/vauth.h include and the CURL_DISABLE_DIGEST_AUTH fallback macro in
+ lib/vauth/vauth.h before reusing the upstream setproxy() cleanup logic.
+- curl-8.7.1 uses tests/data/Makefile.inc and tests/libtest/Makefile.inc
+ instead of the upstream Automake lists.
+
+(cherry picked from commit c1cfdf59acbaf9504c4578d4cf56cdd7c8594507)
+Signed-off-by: Anil Dongare <adongare@cisco.com>
+---
+ lib/setopt.c | 17 ++++-
+ lib/vauth/vauth.h | 2 +
+ tests/data/Makefile.inc | 1 +
+ tests/data/test1588 | 105 ++++++++++++++++++++++++++
+ tests/libtest/Makefile.inc | 5 +-
+ tests/libtest/lib1588.c | 147 +++++++++++++++++++++++++++++++++++++
+ 6 files changed, 274 insertions(+), 3 deletions(-)
+ create mode 100644 tests/data/test1588
+ create mode 100644 tests/libtest/lib1588.c
+
+diff --git a/lib/setopt.c b/lib/setopt.c
+index 8a5a5d7..3de3047 100644
+--- a/lib/setopt.c
++++ b/lib/setopt.c
+@@ -51,6 +51,7 @@
+ #include "altsvc.h"
+ #include "hsts.h"
+ #include "tftp.h"
++#include "vauth/vauth.h"
+ #include "strdup.h"
+ /* The last 3 #include files should be in this order */
+ #include "curl_printf.h"
+@@ -76,6 +77,19 @@ CURLcode Curl_setstropt(char **charp, const char *s)
+ return CURLE_OK;
+ }
+
++#ifndef CURL_DISABLE_PROXY
++static CURLcode setproxy(struct Curl_easy *data, const char *proxy)
++{
++ if((data->set.str[STRING_PROXY] && proxy) &&
++ !strcmp(data->set.str[STRING_PROXY], proxy))
++ return CURLE_OK;
++
++ Curl_auth_digest_cleanup(&data->state.proxydigest);
++ memset(&data->state.authproxy, 0, sizeof(data->state.authproxy));
++ return Curl_setstropt(&data->set.str[STRING_PROXY], proxy);
++}
++#endif
++
+ CURLcode Curl_setblobopt(struct curl_blob **blobp,
+ const struct curl_blob *blob)
+ {
+@@ -1139,8 +1153,7 @@ CURLcode Curl_vsetopt(struct Curl_easy *data, CURLoption option, va_list param)
+ * Setting it to NULL, means no proxy but allows the environment variables
+ * to decide for us (if CURLOPT_SOCKS_PROXY setting it to NULL).
+ */
+- result = Curl_setstropt(&data->set.str[STRING_PROXY],
+- va_arg(param, char *));
++ result = setproxy(data, va_arg(param, char *));
+ break;
+
+ case CURLOPT_PRE_PROXY:
+diff --git a/lib/vauth/vauth.h b/lib/vauth/vauth.h
+index 9da0540..bf5c7a3 100644
+--- a/lib/vauth/vauth.h
++++ b/lib/vauth/vauth.h
+@@ -119,6 +119,8 @@ CURLcode Curl_auth_create_digest_http_message(struct Curl_easy *data,
+
+ /* This is used to clean up the digest specific data */
+ void Curl_auth_digest_cleanup(struct digestdata *digest);
++#else
++#define Curl_auth_digest_cleanup(x)
+ #endif /* !CURL_DISABLE_DIGEST_AUTH */
+
+ #ifdef USE_GSASL
+diff --git a/tests/data/Makefile.inc b/tests/data/Makefile.inc
+index 136b961..aff6a01 100644
+--- a/tests/data/Makefile.inc
++++ b/tests/data/Makefile.inc
+@@ -200,6 +200,7 @@ test1540 test1541 test1542 test1543 test1544 test1545 \
+ test1550 test1551 test1552 test1553 test1554 test1555 test1556 test1557 \
+ test1558 test1559 test1560 test1561 test1562 test1563 test1564 test1565 \
+ test1566 test1567 test1568 test1569 test1570 \
++test1588 \
+ \
+ test1590 test1591 test1592 test1593 test1594 test1595 test1596 test1597 \
+ test1598 \
+diff --git a/tests/data/test1588 b/tests/data/test1588
+new file mode 100644
+index 0000000..0199fa8
+--- /dev/null
++++ b/tests/data/test1588
+@@ -0,0 +1,105 @@
++<?xml version="1.0" encoding="US-ASCII"?>
++<testcase>
++<info>
++<keywords>
++HTTP
++HTTP GET
++HTTP proxy
++HTTP proxy Digest auth
++multi
++</keywords>
++</info>
++
++# Server-side
++<reply>
++
++# this is returned first since we get no proxy-auth
++<data crlf="headers">
++HTTP/1.1 407 Authorization Required to proxy me my dear
++Proxy-Authenticate: Digest realm="weirdorealm", nonce="12345"
++Content-Length: 33
++
++And you should ignore this data.
++</data>
++
++# then this is returned when we get proxy-auth
++<data1000 crlf="headers">
++HTTP/1.1 200 OK
++Content-Length: 21
++Server: no
++
++Nice proxy auth sir!
++</data1000>
++
++<datacheck crlf="headers">
++HTTP/1.1 407 Authorization Required to proxy me my dear
++Proxy-Authenticate: Digest realm="weirdorealm", nonce="12345"
++Content-Length: 33
++
++HTTP/1.1 200 OK
++Content-Length: 21
++Server: no
++
++Nice proxy auth sir!
++HTTP/1.1 407 Authorization Required to proxy me my dear
++Proxy-Authenticate: Digest realm="weirdorealm", nonce="12345"
++Content-Length: 33
++
++HTTP/1.1 200 OK
++Content-Length: 21
++Server: no
++
++Nice proxy auth sir!
++</datacheck>
++</reply>
++
++# Client-side
++<client>
++<server>
++http
++</server>
++<tool>
++lib%TESTNUMBER
++</tool>
++<features>
++!SSPI
++crypto
++proxy
++digest
++</features>
++<name>
++HTTP proxy auth Digest, then change proxy and do it again
++</name>
++<command>
++http://test.remote.example.com/path/%TESTNUMBER %HOSTIP %HTTPPORT silly:person custom.set.host.name
++</command>
++</client>
++
++# Verify data after the test has been "shot"
++<verify>
++<protocol crlf="headers">
++GET http://test.remote.example.com/path/1588 HTTP/1.1
++Host: test.remote.example.com
++Accept: */*
++Proxy-Connection: Keep-Alive
++
++GET http://test.remote.example.com/path/1588 HTTP/1.1
++Host: test.remote.example.com
++Proxy-Authorization: Digest username="silly", realm="weirdorealm", nonce="12345", uri="/path/1588", response="d0b2f000c7e3fca24452b5810713404a"
++Accept: */*
++Proxy-Connection: Keep-Alive
++
++GET http://test.remote.example.com/path/1588 HTTP/1.1
++Host: test.remote.example.com
++Accept: */*
++Proxy-Connection: Keep-Alive
++
++GET http://test.remote.example.com/path/1588 HTTP/1.1
++Host: test.remote.example.com
++Proxy-Authorization: Digest username="silly", realm="weirdorealm", nonce="12345", uri="/path/1588", response="d0b2f000c7e3fca24452b5810713404a"
++Accept: */*
++Proxy-Connection: Keep-Alive
++
++</protocol>
++</verify>
++</testcase>
+diff --git a/tests/libtest/Makefile.inc b/tests/libtest/Makefile.inc
+index 0f140eb..21f3c44 100644
+--- a/tests/libtest/Makefile.inc
++++ b/tests/libtest/Makefile.inc
+@@ -62,7 +62,7 @@ noinst_PROGRAMS = chkhostname libauthretry libntlmconnect libprereq \
+ lib1540 lib1541 lib1542 lib1543 lib1545 \
+ lib1550 lib1551 lib1552 lib1553 lib1554 lib1555 lib1556 lib1557 \
+ lib1558 lib1559 lib1560 lib1564 lib1565 lib1567 lib1568 lib1569 \
+- lib1591 lib1592 lib1593 lib1594 lib1596 lib1597 lib1598 \
++ lib1588 lib1591 lib1592 lib1593 lib1594 lib1596 lib1597 lib1598 \
+ \
+ lib1662 \
+ \
+@@ -690,6 +690,9 @@ lib2504_LDADD = $(TESTUTIL_LIBS)
+ lib2506_SOURCES = lib2506.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
+ lib2506_LDADD = $(TESTUTIL_LIBS)
+
++lib1588_SOURCES = lib1588.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
++lib1588_LDADD = $(TESTUTIL_LIBS)
++
+ lib3010_SOURCES = lib3010.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
+ lib3010_LDADD = $(TESTUTIL_LIBS)
+
+diff --git a/tests/libtest/lib1588.c b/tests/libtest/lib1588.c
+new file mode 100644
+index 0000000..46d6a83
+--- /dev/null
++++ b/tests/libtest/lib1588.c
+@@ -0,0 +1,147 @@
++/***************************************************************************
++ * _ _ ____ _
++ * Project ___| | | | _ \| |
++ * / __| | | | |_) | |
++ * | (__| |_| | _ <| |___
++ * \___|\___/|_| \_\_____|
++ *
++ * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
++ *
++ * This software is licensed as described in the file COPYING, which
++ * you should have received as part of this distribution. The terms
++ * are also available at https://curl.se/docs/copyright.html.
++ *
++ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
++ * copies of the Software, and permit persons to whom the Software is
++ * furnished to do so, under the terms of the COPYING file.
++ *
++ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
++ * KIND, either express or implied.
++ *
++ * SPDX-License-Identifier: curl
++ *
++ ***************************************************************************/
++/*
++ * argv1 = URL
++ * argv2 = proxy host
++ * argv3 = proxy port
++ * argv4 = proxyuser:password
++ */
++
++#include "first.h"
++
++static CURLcode init1588(CURL *curl, const char *url,
++ const char *userpwd, const char *proxy)
++{
++ CURLcode result = CURLE_OK;
++
++ res_easy_setopt(curl, CURLOPT_URL, url);
++ if(result)
++ goto init_failed;
++
++ res_easy_setopt(curl, CURLOPT_PROXY, proxy);
++ if(result)
++ goto init_failed;
++
++ res_easy_setopt(curl, CURLOPT_PROXYUSERPWD, userpwd);
++ if(result)
++ goto init_failed;
++
++ res_easy_setopt(curl, CURLOPT_PROXYAUTH, CURLAUTH_DIGEST);
++ if(result)
++ goto init_failed;
++
++ res_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
++ if(result)
++ goto init_failed;
++#if 0
++ res_easy_setopt(curl, CURLOPT_HTTPPROXYTUNNEL, 1L);
++ if(result)
++ goto init_failed;
++#endif
++
++ res_easy_setopt(curl, CURLOPT_HEADER, 1L);
++ if(result)
++ goto init_failed;
++
++ return CURLE_OK; /* success */
++
++init_failed:
++ return result; /* failure */
++}
++
++static CURLcode run1588(CURL *curl, const char *url, const char *userpwd,
++ const char *proxy)
++{
++ CURLcode result = CURLE_OK;
++
++ result = init1588(curl, url, userpwd, proxy);
++ if(result)
++ return result;
++
++ return curl_easy_perform(curl);
++}
++
++static CURLcode test_lib1588(const char *URL)
++{
++ CURLcode result = CURLE_OK;
++ CURL *curl = NULL;
++ const char *proxyuserpws = libtest_arg4;
++ struct curl_slist *host = NULL;
++ struct curl_slist *host2 = NULL;
++ char proxy1_resolve[128];
++ char proxy2_resolve[128];
++ char proxy1_connect[128];
++ char proxy2_connect[128];
++
++ if(test_argc < 3)
++ return TEST_ERR_MAJOR_BAD;
++
++ curl_msnprintf(proxy1_resolve, sizeof(proxy1_resolve),
++ "firstproxy:%s:%s", libtest_arg3, libtest_arg2);
++ curl_msnprintf(proxy2_resolve, sizeof(proxy2_resolve),
++ "secondproxy:%s:%s", libtest_arg3, libtest_arg2);
++
++ /* we connect to the fake host name but the right port number */
++ curl_msnprintf(proxy1_connect, sizeof(proxy1_connect),
++ "firstproxy:%s", libtest_arg3);
++ curl_msnprintf(proxy2_connect, sizeof(proxy2_connect),
++ "secondproxy:%s", libtest_arg3);
++
++ res_global_init(CURL_GLOBAL_ALL);
++ if(result)
++ return result;
++
++ curl = curl_easy_init();
++ if(!curl) {
++ curl_mfprintf(stderr, "curl_easy_init() failed\n");
++ curl_global_cleanup();
++ return TEST_ERR_MAJOR_BAD;
++ }
++
++ host = curl_slist_append(NULL, proxy1_resolve);
++ if(!host)
++ goto test_cleanup;
++ host2 = curl_slist_append(host, proxy2_resolve);
++ if(!host2)
++ goto test_cleanup;
++ host = host2;
++
++ start_test_timing();
++
++ easy_setopt(curl, CURLOPT_RESOLVE, host);
++
++ result = run1588(curl, URL, proxyuserpws, proxy1_connect);
++ if(result)
++ goto test_cleanup;
++
++ curl_mfprintf(stderr, "lib1588: now we do the request again\n");
++
++ result = run1588(curl, URL, proxyuserpws, proxy2_connect);
++
++test_cleanup:
++ curl_easy_cleanup(curl);
++ curl_global_cleanup();
++ curl_slist_free_all(host);
++ return result;
++}
+--
+2.43.7
@@ -40,6 +40,7 @@ SRC_URI = " \
file://CVE-2026-6253.patch \
file://CVE-2026-6276.patch \
file://CVE-2026-6429.patch \
+ file://CVE-2026-7168.patch \
"
SRC_URI:append:class-nativesdk = " \