2.7.18.15: eMudhra ssl distrust (CVE-2026-115557) + ensurepip pip 20.3.4.post3 / setuptools 44.1.1.post3

Include/patchlevel.h

@@ -27,7 +27,7 @@
 #define PY_RELEASE_SERIAL	0
 
 /* Version as a string */
-#define PY_VERSION      	"2.7.18.14"
+#define PY_VERSION      	"2.7.18.15"
 /*--end constants--*/
 
 /* Subversion Revision number of this file (not of the repository). Empty

Lib/ensurepip/__init__.py

@@ -12,9 +12,9 @@
 __all__ = ["version", "bootstrap"]
 
 
-_SETUPTOOLS_VERSION = "41.2.0"
+_SETUPTOOLS_VERSION = "44.1.1.post3"
 
-_PIP_VERSION = "19.2.3"
+_PIP_VERSION = "20.3.4.post4"
 
 _PROJECTS = [
     ("setuptools", _SETUPTOOLS_VERSION),
@@ -28,8 +28,8 @@ def _run_pip(args, additional_paths=None):
         sys.path = additional_paths + sys.path
 
     # Install the bundled software
-    import pip._internal
-    return pip._internal.main(args)
+    from pip._internal.cli.main import main as _main
+    return _main(args)
 
 
 def version():

Lib/test/test_ssl.py

@@ -20,7 +20,9 @@
 import errno
 import pprint
 import shutil
+import tempfile
 import urllib2
+import zipfile
 import traceback
 import weakref
 import platform
@@ -80,6 +82,19 @@ def data_file(*name):
 NULLBYTECERT = data_file("nullbytecert.pem")
 TALOS_INVALID_CRLDP = data_file("talos-2019-0758.pem")
 
+# gh-160040: a leaf signed by a compromised eMudhra intermediate whose public
+# key is on the _ssl distrusted list. The chain to distrusted_root.pem is
+# otherwise valid.
+# The PEMs live in a password-protected zip so the compromised eMudhra certs
+# don't trip security scanners that cannot tell internal test fixtures from
+# production secrets and flag any certificate or private key they find.  It is
+# encrypted, not merely zipped, because such scanners read inside plain archives.
+# The password is fixed, public, and not a secret; it only keeps the archive
+# from storing the PEMs in the clear.
+DISTRUSTED_SPKI_ZIP = data_file("distrusted.zip")
+DISTRUSTED_SPKI_CHOSEN_KNIGHT = b"Brave Sir Robin"  # not a secret, see comment
+DISTRUSTED_SPKI_HOSTNAME = "localhost"
+
 DHFILE = data_file("ffdh3072.pem")
 BYTES_DHFILE = DHFILE.encode(sys.getfilesystemencoding())
 
@@ -2279,6 +2294,39 @@ def test_crl_check(self):
                     cert = s.getpeercert()
                     self.assertTrue(cert, "Can't get peer certificate.")
 
+        def test_distrusted_spki(self):
+            # gh-160040: the server chain is otherwise valid, but the eMudhra
+            # intermediate's public key is on the _ssl distrusted list, so
+            # verification rejects it.
+            client_context = ssl.SSLContext(ssl.PROTOCOL_TLS)
+            client_context.verify_mode = ssl.CERT_REQUIRED
+            client_context.check_hostname = True
+            server_context = ssl.SSLContext(ssl.PROTOCOL_TLS)
+            # the contexts load the PEMs now, so the files are only needed here
+            tmpdir = tempfile.mkdtemp()
+            try:
+                with closing(zipfile.ZipFile(DISTRUSTED_SPKI_ZIP)) as z:
+                    z.extractall(tmpdir, pwd=DISTRUSTED_SPKI_CHOSEN_KNIGHT)
+                certdir = os.path.join(tmpdir, "distrusted")
+                client_context.load_verify_locations(
+                    os.path.join(certdir, "distrusted_root.pem"))
+                server_context.load_cert_chain(
+                    os.path.join(certdir, "distrusted_keycert.pem"))
+            finally:
+                shutil.rmtree(tmpdir)
+
+            server = ThreadedEchoServer(context=server_context, chatty=False)
+            with server:
+                with closing(client_context.wrap_socket(
+                        socket.socket(),
+                        server_hostname=DISTRUSTED_SPKI_HOSTNAME)) as s:
+                    # 2.7 has no SSLCertVerificationError/verify_code; the
+                    # X509_V_ERR_CERT_REJECTED reason only reaches the
+                    # message on OpenSSL 1.1.0+.
+                    with self.assertRaisesRegexp(ssl.SSLError,
+                                                 "certificate verify failed"):
+                        s.connect((HOST, server.port))
+
         def test_check_hostname(self):
             if support.verbose:
                 sys.stdout.write("\n")

Misc/NEWS.d/2.7.18.15.rst

@@ -0,0 +1,38 @@
+.. bpo: 0
+.. date: 2026-10-27
+.. nonce: aS$mUd
+.. release date: 2026-10-27
+.. original section: Library
+.. section: Security
+
+Address CVE-2026-115557 (compromised eMudhra intermediate CA keys) in ssl
+
+The :mod:`ssl` module now rejects TLS certificate chains that contain any of
+a set of compromised eMudhra intermediate CA keys (gh-160040, backported from
+the upstream 3.11 security release). The denylist matches the SHA-256 digest
+of each certificate's SubjectPublicKeyInfo, so it also covers cross-signed
+certificates that reuse a distrusted key. A matching certificate fails
+verification with ``X509_V_ERR_CERT_REJECTED`` ("certificate verify
+failed"). The check runs whenever :attr:`SSLContext.verify_mode` is
+``CERT_OPTIONAL`` or ``CERT_REQUIRED``. This is a last line of defense while
+operating-system and bundled trust stores drop the eMudhra/emSign roots.
+
+.. bpo: 0
+.. date: 2026-10-27
+.. nonce: aS$mUd
+.. release date: 2026-10-27
+.. original section: Library
+.. section: Security
+
+Upgrade the pip and setuptools bundled with ensurepip
+
+:mod:`ensurepip` now bundles pip 20.3.4.post4 and setuptools 44.1.1.post3,
+the ActiveState security releases of the last Python 2.7-compatible pip and
+setuptools lines, in place of pip 19.2.3 and setuptools 41.2.0. pip's
+vendored certifi is 2026.10.23.post1, ActiveState's Python 2.7 build of
+certifi 2026.10.23, which removes the emSign ECC Root CA - G3, emSign Root
+CA - C1 and emSign ECC Root CA - C3 roots; emSign Root CA - G1 is the only
+emSign root left. pip's connections go through the :mod:`ssl` module, so the
+eMudhra SPKI denylist above also applies to them (CVE-2026-115557).
+setuptools 44.1.1.post3 includes the fixes for CVE-2022-40897,
+CVE-2024-6345, CVE-2025-47273 and CVE-2026-59890.

Modules/_ssl.c

@@ -68,6 +68,7 @@
 /* Include OpenSSL header files */
 #include "openssl/rsa.h"
 #include "openssl/crypto.h"
+#include "openssl/evp.h"
 #include "openssl/x509.h"
 #include "openssl/x509v3.h"
 #include "openssl/pem.h"
@@ -2600,11 +2601,79 @@ get_verify_mode(PySSLContext *self, void *c)
     return NULL;
 }
 
+#include "_ssl_distrusted_spki.h"
+
+/* Returns 1 if the SHA-256 of the cert's SPKI is on the distrusted list,
+   0 if not (okay), -1 on an internal error. */
+static int
+_cert_has_distrusted_spki(X509 *cert)
+{
+    unsigned char *spki = NULL;
+    unsigned char digest[EVP_MAX_MD_SIZE];
+    unsigned int digest_len = 0;
+    int spki_len, ok;
+    size_t i;
+
+    spki_len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &spki);
+    if (spki_len <= 0 || spki == NULL) {
+        return -1;
+    }
+
+    ok = EVP_Digest(spki, (size_t)spki_len, digest, &digest_len,
+                    EVP_sha256(), NULL);
+    OPENSSL_free(spki);
+    assert(sizeof(_distrusted_spki[0]) == SHA256_DIGEST_LENGTH);
+    if (!ok
+        || digest_len != SHA256_DIGEST_LENGTH
+        || sizeof(_distrusted_spki[0]) != SHA256_DIGEST_LENGTH) {
+        return -1;
+    }
+
+    for (i = 0; i < sizeof(_distrusted_spki) / sizeof(_distrusted_spki[0]); i++) {
+        if (memcmp(digest, _distrusted_spki[i], SHA256_DIGEST_LENGTH) == 0) {
+            return 1;
+        }
+    }
+    return 0;
+}
+
+/* Verify callback, called once per cert. Reject distrusted SPKIs. */
+static int
+_ssl_verify_callback(int preverify_ok, X509_STORE_CTX *x509_ctx)
+{
+    X509 *cert;
+
+    /* Don't override an error OpenSSL already reported for this certificate. */
+    if (!preverify_ok) {
+        return preverify_ok;
+    }
+    cert = X509_STORE_CTX_get_current_cert(x509_ctx);
+    if (cert == NULL) {
+        return preverify_ok;
+    }
+    switch (_cert_has_distrusted_spki(cert)) {
+    case 0:
+        /* okay: not on the distrusted list */
+        return preverify_ok;
+    case 1:
+        /* rejected: public key is on the distrusted list */
+        X509_STORE_CTX_set_error(x509_ctx, X509_V_ERR_CERT_REJECTED);
+        return 0;
+    default:
+        /* internal error */
+#ifdef X509_V_ERR_UNSPECIFIED
+        X509_STORE_CTX_set_error(x509_ctx, X509_V_ERR_UNSPECIFIED);
+#else
+        X509_STORE_CTX_set_error(x509_ctx, X509_V_ERR_APPLICATION_VERIFICATION);
+#endif
+        return 0;
+    }
+}
+
 static int
 set_verify_mode(PySSLContext *self, PyObject *arg, void *c)
 {
     int n, mode;
-    int (*verify_cb)(int, X509_STORE_CTX *) = NULL;
 
     if (!PyArg_Parse(arg, "i", &n))
         return -1;
@@ -2630,9 +2699,7 @@ set_verify_mode(PySSLContext *self, PyObject *arg, void *c)
   /* bpo-37428: newPySSLSocket() sets SSL_VERIFY_POST_HANDSHAKE flag for
      * server sockets and SSL_set_post_handshake_auth() for client. */
 
-    /* keep current verify cb */
-    verify_cb = SSL_CTX_get_verify_callback(self->ctx);
-    SSL_CTX_set_verify(self->ctx, mode, verify_cb);
+    SSL_CTX_set_verify(self->ctx, mode, _ssl_verify_callback);
     return 0;
 }
 

Modules/_ssl_distrusted_spki.h

@@ -0,0 +1,75 @@
+/* Denylist of distrusted SubjectPublicKeyInfo (SPKI).
+ *
+ * Verification rejects any chain with a cert whose SPKI SHA-256 digest is in
+ * the _distrusted_spki table.  We match the key, not a cert fingerprint, so
+ * cross-signs that reuse the key are blocked too.
+ *
+ * This is an extraordinary measure and last line of defense.  Removing trust is
+ * primarily the job of the platform root store. This list only blocks keys while
+ * that update is still propagating to the OS, container images, or root CAs
+ * bundled in Python packages.  The threshold for adding an entry is very high.
+  *
+ * See https://github.com/python/cpython/issues/160040 for the eMudhra discussion.
+ *
+ * To block another key, add the SHA-256 digest bytes of its SPKI:
+ *
+ *     $ openssl x509 -in cert.pem -noout -pubkey | openssl pkey -pubin -outform DER | openssl dgst -sha256 -binary | xxd -i
+ */
+#ifndef Py_SSL_DISTRUSTED_SPKI_H
+#define Py_SSL_DISTRUSTED_SPKI_H
+
+#include "openssl/sha.h"
+
+static const unsigned char _distrusted_spki[][SHA256_DIGEST_LENGTH] = {
+    /* Compromised eMudhra intermediates, https://emudhra.we-have-a-problem.com/ */
+    /* CN=EM OV TLS CA - G3B,O=eMudhra BV,C=NL */
+    {
+        0x43, 0xbf, 0xfa, 0x19, 0xd6, 0xef, 0x65, 0x14, 0x51, 0xf6, 0x84, 0x1e,
+        0x01, 0x99, 0x31, 0xe9, 0x6f, 0x6f, 0x2e, 0xae, 0xff, 0x28, 0xab, 0x4b,
+        0x6f, 0x1c, 0xe4, 0x57, 0x6d, 0xe2, 0x71, 0x7b,
+    },
+    /* CN=EM DV TLS CA - G3C,O=eMudhra Inc,C=US */
+    {
+        0x49, 0xdd, 0x35, 0x3d, 0xc2, 0xb9, 0x19, 0xa3, 0x77, 0x06, 0x45, 0x11,
+        0x7d, 0x0e, 0x60, 0xc1, 0x61, 0x15, 0xe7, 0xd1, 0xbc, 0x25, 0x9e, 0xef,
+        0xe7, 0x34, 0xb0, 0x0e, 0xa4, 0x34, 0xfe, 0x5f,
+    },
+    /* CN=EM EV TLS CA - G3C,O=eMudhra Inc,C=US */
+    {
+        0x5c, 0x06, 0x60, 0xa2, 0xb1, 0x64, 0x91, 0x0d, 0x8f, 0xf5, 0x89, 0xc1,
+        0x8e, 0x14, 0x55, 0x2e, 0x9e, 0x0e, 0xc2, 0x37, 0xdc, 0xef, 0xe2, 0xcb,
+        0x73, 0x6d, 0x41, 0xa4, 0x81, 0x1f, 0x81, 0xa0,
+    },
+    /* CN=EM OV TLS CA - G3C,O=eMudhra Inc,C=US */
+    {
+        0x63, 0xec, 0xef, 0xee, 0x43, 0x1d, 0x49, 0x52, 0x3b, 0xc1, 0x13, 0x6c,
+        0x4e, 0x72, 0xd0, 0x20, 0x6a, 0x47, 0x70, 0x86, 0xca, 0xf6, 0x06, 0xcd,
+        0x5c, 0xf0, 0x25, 0x68, 0x6c, 0x10, 0x9c, 0xf8,
+    },
+    /* CN=EM OV CS CA - G3C,O=eMudhra Inc,C=US */
+    {
+        0x92, 0xc0, 0x63, 0xd6, 0x7e, 0x8f, 0x14, 0xdb, 0x71, 0xd2, 0x88, 0xe1,
+        0x12, 0x66, 0xff, 0xda, 0xf6, 0x9c, 0xbf, 0x11, 0x5f, 0x7b, 0xab, 0x14,
+        0xf3, 0xbc, 0x2f, 0x68, 0xd2, 0x5e, 0x0e, 0x30,
+    },
+    /* CN=EM EV TLS CA - G3B,O=eMudhra BV,C=NL */
+    {
+        0xe0, 0x25, 0x4c, 0x7f, 0xcd, 0xc2, 0x65, 0xe2, 0xf0, 0xf8, 0xa4, 0x28,
+        0xda, 0xbb, 0x75, 0xab, 0x4a, 0xe0, 0x39, 0xb4, 0x87, 0x2d, 0x62, 0xf5,
+        0xee, 0x57, 0xf0, 0x87, 0x7d, 0x5a, 0x8a, 0x41,
+    },
+    /* CN=EM DV TLS CA - G3B,O=eMudhra BV,C=NL */
+    {
+        0xeb, 0xed, 0x64, 0x75, 0xc2, 0xc2, 0xd8, 0x0f, 0xcb, 0x19, 0x9f, 0x3f,
+        0xe8, 0xdd, 0x6e, 0x6b, 0x3c, 0xe6, 0x0b, 0x77, 0xeb, 0x15, 0xd4, 0xe4,
+        0x2c, 0x3d, 0xec, 0x0c, 0x6f, 0x5b, 0x51, 0x05,
+    },
+    /* CN=EM OV CS CA - G3B,O=eMudhra BV,C=NL */
+    {
+        0xec, 0x4f, 0xfa, 0x1a, 0xd0, 0xac, 0x88, 0x08, 0x13, 0x14, 0xb7, 0xaa,
+        0xff, 0xef, 0x6a, 0x91, 0xf9, 0x7c, 0xd5, 0x72, 0x91, 0xbb, 0x5b, 0xa6,
+        0x86, 0xc5, 0x41, 0x5f, 0x5e, 0xb4, 0xf6, 0xb6,
+    },
+};
+
+#endif /* !Py_SSL_DISTRUSTED_SPKI_H */

PCbuild/_ssl.vcxproj

@@ -65,6 +65,9 @@
       <AdditionalDependencies>ws2_32.lib;crypt32.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClInclude Include="..\Modules\_ssl_distrusted_spki.h" />
+  </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\Modules\_ssl.c" />
     <ClCompile Include="$(opensslIncludeDir)\applink.c">

PCbuild/_ssl.vcxproj.filters

@@ -4,10 +4,18 @@
     <Filter Include="Source Files">
       <UniqueIdentifier>{695348f7-e9f6-4fe1-bc03-5f08ffc8095b}</UniqueIdentifier>
     </Filter>
+    <Filter Include="Header Files">
+      <UniqueIdentifier>{7c1bd5da-8912-4107-b6ac-f3930f2d90c7}</UniqueIdentifier>
+    </Filter>
     <Filter Include="Resource Files">
       <UniqueIdentifier>{1b18a2e6-040d-46c7-a9ac-ac2ec64fb5d6}</UniqueIdentifier>
     </Filter>
   </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\Modules\_ssl_distrusted_spki.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+  </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\Modules\_ssl.c">
       <Filter>Source Files</Filter>

Tools/msi/msi.py

@@ -1060,6 +1060,7 @@ def add_files(db):
             lib.glob("*.pem")
             lib.glob("*.pck")
             lib.add_file("zipdir.zip")
+            lib.add_file("distrusted.zip")
         if dir=='tests' and parent.physical=='distutils':
             lib.add_file("Setup.sample")
         if dir=='audiodata':

setup.py

@@ -879,7 +879,8 @@ def detect_modules(self):
                                    include_dirs = ssl_incs,
                                    library_dirs = ssl_libs,
                                    libraries = ['ssl', 'crypto'],
-                                   depends = ['socketmodule.h']), )
+                                   depends = ['socketmodule.h',
+                                              '_ssl_distrusted_spki.h']), )
         else:
             missing.append('_ssl')