[OE-core][scarthgap][patch 2/2] python3-pyopenssl: Fix CVE-2026-27459

[Vijay Anusuri <vanusuri@mvista.com>]

Pick patch mentioned in NVD

[1] https://nvd.nist.gov/vuln/detail/CVE-2026-27459
[2] https://ubuntu.com/security/CVE-2026-27459

Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
---
 .../python3-pyopenssl/CVE-2026-27459.patch    | 109 ++++++++++++++++++
 .../python/python3-pyopenssl_24.0.0.bb        |   1 +
 2 files changed, 110 insertions(+)
 create mode 100644 meta/recipes-devtools/python/python3-pyopenssl/CVE-2026-27459.patch

diff --git a/meta/recipes-devtools/python/python3-pyopenssl/CVE-2026-27459.patch b/meta/recipes-devtools/python/python3-pyopenssl/CVE-2026-27459.patch
new file mode 100644
index 0000000000..f75540f96e
--- /dev/null
+++ b/meta/recipes-devtools/python/python3-pyopenssl/CVE-2026-27459.patch
@@ -0,0 +1,109 @@
+From 57f09bb4bb051d3bc2a1abd36e9525313d5cd408 Mon Sep 17 00:00:00 2001
+From: Alex Gaynor <alex.gaynor@gmail.com>
+Date: Wed, 18 Feb 2026 07:46:15 -0500
+Subject: [PATCH] Fix buffer overflow in DTLS cookie generation callback
+ (#1479)
+
+The cookie generate callback copied user-returned bytes into a
+fixed-size native buffer without enforcing a maximum length. A
+callback returning more than DTLS1_COOKIE_LENGTH bytes would overflow
+the OpenSSL-provided buffer, corrupting adjacent memory.
+
+Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
+
+Upstream-Status: Backport [https://github.com/pyca/pyopenssl/commit/57f09bb4bb051d3bc2a1abd36e9525313d5cd408]
+CVE: CVE-2026-27459
+Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
+---
+ CHANGELOG.rst      |  1 +
+ src/OpenSSL/SSL.py |  7 +++++++
+ tests/test_ssl.py  | 38 ++++++++++++++++++++++++++++++++++++++
+ 3 files changed, 46 insertions(+)
+
+diff --git a/CHANGELOG.rst b/CHANGELOG.rst
+index 12e60e4..6041fdc 100644
+--- a/CHANGELOG.rst
++++ b/CHANGELOG.rst
+@@ -16,6 +16,7 @@ Deprecations:
+ Changes:
+ ^^^^^^^^
+ 
++- Properly raise an error if a DTLS cookie callback returned a cookie longer than ``DTLS1_COOKIE_LENGTH`` bytes. Previously this would result in a buffer-overflow.
+ - Added ``OpenSSL.SSL.Connection.get_selected_srtp_profile`` to determine which SRTP profile was negotiated.
+   `#1279 <https://github.com/pyca/pyopenssl/pull/1279>`_.
+ - ``Context.set_tlsext_servername_callback`` now handles exceptions raised in the callback by calling ``sys.excepthook`` and returning a fatal TLS alert. Previously, exceptions were silently swallowed and the handshake would proceed as if the callback had succeeded.
+diff --git a/src/OpenSSL/SSL.py b/src/OpenSSL/SSL.py
+index a6263c4..2e4da78 100644
+--- a/src/OpenSSL/SSL.py
++++ b/src/OpenSSL/SSL.py
+@@ -691,11 +691,18 @@ class _CookieGenerateCallbackHelper(_CallbackExceptionHelper):
+     def __init__(self, callback):
+         _CallbackExceptionHelper.__init__(self)
+ 
++        max_cookie_len = getattr(_lib, "DTLS1_COOKIE_LENGTH", 255)
++
+         @wraps(callback)
+         def wrapper(ssl, out, outlen):
+             try:
+                 conn = Connection._reverse_mapping[ssl]
+                 cookie = callback(conn)
++                if len(cookie) > max_cookie_len:
++                    raise ValueError(
++                        f"Cookie too long (got {len(cookie)} bytes, "
++                        f"max {max_cookie_len})"
++                    )
+                 out[0 : len(cookie)] = cookie
+                 outlen[0] = len(cookie)
+                 return 1
+diff --git a/tests/test_ssl.py b/tests/test_ssl.py
+index 55489b9..683e368 100644
+--- a/tests/test_ssl.py
++++ b/tests/test_ssl.py
+@@ -4560,6 +4560,44 @@ class TestDTLS:
+     def test_it_works_with_srtp(self):
+         self._test_handshake_and_data(srtp_profile=b"SRTP_AES128_CM_SHA1_80")
+ 
++    def test_cookie_generate_too_long(self) -> None:
++        s_ctx = Context(DTLS_METHOD)
++
++        def generate_cookie(ssl: Connection) -> bytes:
++            return b"\x00" * 256
++
++        def verify_cookie(ssl: Connection, cookie: bytes) -> bool:
++            return True
++
++        s_ctx.set_cookie_generate_callback(generate_cookie)
++        s_ctx.set_cookie_verify_callback(verify_cookie)
++        s_ctx.use_privatekey(load_privatekey(FILETYPE_PEM, server_key_pem))
++        s_ctx.use_certificate(load_certificate(FILETYPE_PEM, server_cert_pem))
++        s_ctx.set_options(OP_NO_QUERY_MTU)
++        s = Connection(s_ctx)
++        s.set_accept_state()
++
++        c_ctx = Context(DTLS_METHOD)
++        c_ctx.set_options(OP_NO_QUERY_MTU)
++        c = Connection(c_ctx)
++        c.set_connect_state()
++
++        c.set_ciphertext_mtu(1500)
++        s.set_ciphertext_mtu(1500)
++
++        # Client sends ClientHello
++        try:
++            c.do_handshake()
++        except SSL.WantReadError:
++            pass
++        chunk = c.bio_read(self.LARGE_BUFFER)
++        s.bio_write(chunk)
++
++        # Server tries DTLSv1_listen, which triggers cookie generation.
++        # The oversized cookie should raise ValueError.
++        with pytest.raises(ValueError, match="Cookie too long"):
++            s.DTLSv1_listen()
++
+     def test_timeout(self, monkeypatch):
+         c_ctx = Context(DTLS_METHOD)
+         c = Connection(c_ctx)
+-- 
+2.43.0
+
diff --git a/meta/recipes-devtools/python/python3-pyopenssl_24.0.0.bb b/meta/recipes-devtools/python/python3-pyopenssl_24.0.0.bb
index bc0b568a46..94a70aa17d 100644
--- a/meta/recipes-devtools/python/python3-pyopenssl_24.0.0.bb
+++ b/meta/recipes-devtools/python/python3-pyopenssl_24.0.0.bb
@@ -12,6 +12,7 @@ inherit pypi setuptools3
 
 SRC_URI += " \
     file://CVE-2026-27448.patch \
+    file://CVE-2026-27459.patch \
 "
 
 PACKAGES =+ "${PN}-tests"
-- 
2.43.0