[OE-core][scarthgap][PATCH] python3-idna: Fix CVE-2026-45409

[OE-core][scarthgap][PATCH] python3-idna: Fix CVE-2026-45409

[Hetvi Thakar -X (hthakar - E INFOCHIPS PRIVATE LIMITED at Cisco)]

From: Hetvi Thakar <hthakar@cisco.com>

This patch applies the complete upstream fix chain for
CVE-2026-45409. Commit [1] introduces early domain-length rejection
required by [2]. Commit [2] is the v3.14 fix identified by [5], and
commit [3] extends the protection to per-label conversions and codec
support to complete the v3.15 fix described in [4].

[1] https://github.com/kjd/idna/commit/c0dda4501df5
[2] https://github.com/kjd/idna/commit/628fef84d3ed
[3] https://github.com/kjd/idna/commit/e1cb465b6376
[4] https://github.com/kjd/idna/security/advisories/GHSA-65pc-fj4g-8rjx
[5] https://security-tracker.debian.org/tracker/CVE-2026-45409

Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
---
 .../python3-idna/CVE-2026-45409_p1.patch      | 75 +++++++++++++++++++
 .../python3-idna/CVE-2026-45409_p2.patch      | 48 ++++++++++++
 .../python3-idna/CVE-2026-45409_p3.patch      | 72 ++++++++++++++++++
 .../python/python3-idna_3.7.bb                |  5 ++
 4 files changed, 200 insertions(+)
 create mode 100644 meta/recipes-devtools/python/python3-idna/CVE-2026-45409_p1.patch
 create mode 100644 meta/recipes-devtools/python/python3-idna/CVE-2026-45409_p2.patch
 create mode 100644 meta/recipes-devtools/python/python3-idna/CVE-2026-45409_p3.patch

diff --git a/meta/recipes-devtools/python/python3-idna/CVE-2026-45409_p1.patch b/meta/recipes-devtools/python/python3-idna/CVE-2026-45409_p1.patch
new file mode 100644
index 0000000000..02a8090b84
--- /dev/null
+++ b/meta/recipes-devtools/python/python3-idna/CVE-2026-45409_p1.patch
@@ -0,0 +1,75 @@
+From b34cd8399981324b361ae4f2b8e0eb77444ae0e3 Mon Sep 17 00:00:00 2001
+From: Kim Davies <kim@cynosure.com.au>
+Date: Sun, 10 May 2026 08:47:22 -0700
+Subject: [PATCH 1/3] Merge commit from fork
+
+CVE: CVE-2026-45409
+Upstream-Status: Backport [https://github.com/kjd/idna/commit/c0dda4501df5d91c3181ce6f962dc5de74e82cc1]
+
+Backport Changes:
+- Omit the HISTORY.rst hunk because it documents the upstream 3.14
+  release and is not applicable to the Scarthgap 3.7 source.
+
+(cherry picked from commit c0dda4501df5d91c3181ce6f962dc5de74e82cc1)
+Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
+---
+ idna/core.py       | 14 ++++++++++++++
+ tests/test_idna.py | 13 +++++++++++++
+ 2 files changed, 27 insertions(+)
+
+diff --git a/idna/core.py b/idna/core.py
+index 0dae61a..a549326 100644
+--- a/idna/core.py
++++ b/idna/core.py
+@@ -340,6 +340,15 @@ def encode(s: Union[str, bytes, bytearray], strict: bool = False, uts46: bool =
+             raise IDNAError('should pass a unicode string to the function rather than a byte string.')
+     if uts46:
+         s = uts46_remap(s, std3_rules, transitional)
++
++    # Reject inputs that exceed the maximum DNS domain length up-front.
++    # Each codepoint in a U-label contributes at least one octet to its
++    # A-label form, so any input longer than the domain limit cannot
++    # produce a valid A-domain. Short-circuiting here prevents per-label
++    # validation from being driven into quadratic time
++    if len(s) > 254:
++        raise IDNAError("Domain too long")
++
+     trailing_dot = False
+     result = []
+     if strict:
+@@ -373,6 +382,11 @@ def decode(s: Union[str, bytes, bytearray], strict: bool = False, uts46: bool =
+         raise IDNAError('Invalid ASCII in A-label')
+     if uts46:
+         s = uts46_remap(s, std3_rules, False)
++    # See encode() for rationale; the same bound applies because every
++    # legal A-domain is at most 254 octets and every codepoint of a
++    # legal U-domain contributes at least one octet to its A-form.
++    if len(s) > 254:
++        raise IDNAError("Domain too long")
+     trailing_dot = False
+     result = []
+     if not strict:
+diff --git a/tests/test_idna.py b/tests/test_idna.py
+index 81afb32..5001b48 100755
+--- a/tests/test_idna.py
++++ b/tests/test_idna.py
+@@ -78,6 +78,19 @@ class IDNATests(unittest.TestCase):
+         self.assertFalse(idna.valid_label_length('a' * 64))
+         self.assertRaises(idna.IDNAError, idna.encode, 'a' * 64)
+ 
++    def test_oversized_input_rejected_promptly(self):
++        # GHSA-65pc-fj4g-8rjx: encode/decode must reject inputs that
++        # exceed the maximum DNS domain length before per-codepoint
++        # validation runs, so labels dominated by CONTEXTO codepoints
++        # cannot drive validation into quadratic time.
++        import time
++
++        for payload in ("٠" * 8000, "・" * 8000 + "漢"):
++            start = time.perf_counter()
++            self.assertRaises(idna.IDNAError, idna.encode, payload)
++            self.assertRaises(idna.IDNAError, idna.decode, payload)
++            self.assertLess(time.perf_counter() - start, 1.0)
++
+     def test_check_bidi(self):
+ 
+         l = '\u0061'
diff --git a/meta/recipes-devtools/python/python3-idna/CVE-2026-45409_p2.patch b/meta/recipes-devtools/python/python3-idna/CVE-2026-45409_p2.patch
new file mode 100644
index 0000000000..a79e1e9c20
--- /dev/null
+++ b/meta/recipes-devtools/python/python3-idna/CVE-2026-45409_p2.patch
@@ -0,0 +1,48 @@
+From fabb538f1885a135e48a60de2e3c656d965e861d Mon Sep 17 00:00:00 2001
+From: Kim Davies <kim@cynosure.com.au>
+Date: Sun, 10 May 2026 12:44:47 -0700
+Subject: [PATCH 2/3] Use valid_string_length() for early oversized-input check
+
+CVE: CVE-2026-45409
+Upstream-Status: Backport [https://github.com/kjd/idna/commit/628fef84d3eda59321c21127e73dcd873db23ead]
+
+(cherry picked from commit 628fef84d3eda59321c21127e73dcd873db23ead)
+Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
+---
+ idna/core.py | 16 ++++++----------
+ 1 file changed, 6 insertions(+), 10 deletions(-)
+
+diff --git a/idna/core.py b/idna/core.py
+index a549326..4a9fc75 100644
+--- a/idna/core.py
++++ b/idna/core.py
+@@ -341,12 +341,9 @@ def encode(s: Union[str, bytes, bytearray], strict: bool = False, uts46: bool =
+     if uts46:
+         s = uts46_remap(s, std3_rules, transitional)
+ 
+-    # Reject inputs that exceed the maximum DNS domain length up-front.
+-    # Each codepoint in a U-label contributes at least one octet to its
+-    # A-label form, so any input longer than the domain limit cannot
+-    # produce a valid A-domain. Short-circuiting here prevents per-label
+-    # validation from being driven into quadratic time
+-    if len(s) > 254:
++    # Reject inputs that exceed the maximum DNS domain length up-front
++    # to avoid expensive computation on long inputs.
++    if not valid_string_length(s, trailing_dot=True):
+         raise IDNAError("Domain too long")
+ 
+     trailing_dot = False
+@@ -382,10 +379,9 @@ def decode(s: Union[str, bytes, bytearray], strict: bool = False, uts46: bool =
+         raise IDNAError('Invalid ASCII in A-label')
+     if uts46:
+         s = uts46_remap(s, std3_rules, False)
+-    # See encode() for rationale; the same bound applies because every
+-    # legal A-domain is at most 254 octets and every codepoint of a
+-    # legal U-domain contributes at least one octet to its A-form.
+-    if len(s) > 254:
++    # Reject inputs that exceed the maximum DNS domain length up-front
++    # to avoid expensive computation on long inputs.
++    if not valid_string_length(s, trailing_dot=True):
+         raise IDNAError("Domain too long")
+     trailing_dot = False
+     result = []
diff --git a/meta/recipes-devtools/python/python3-idna/CVE-2026-45409_p3.patch b/meta/recipes-devtools/python/python3-idna/CVE-2026-45409_p3.patch
new file mode 100644
index 0000000000..2ebbd5c13d
--- /dev/null
+++ b/meta/recipes-devtools/python/python3-idna/CVE-2026-45409_p3.patch
@@ -0,0 +1,72 @@
+From 22acbaae97c3698005e69555eb4ebccc168b2fff Mon Sep 17 00:00:00 2001
+From: metsw24-max <metsw24@gmail.com>
+Date: Mon, 11 May 2026 20:59:30 +0530
+Subject: [PATCH 3/3] Enforce early length limits in check_label
+
+CVE: CVE-2026-45409
+Upstream-Status: Backport [https://github.com/kjd/idna/commit/e1cb465b6376f33306a26f467d197edbcd01c4b9]
+
+(cherry picked from commit e1cb465b6376f33306a26f467d197edbcd01c4b9)
+Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
+---
+ idna/core.py       | 11 +++++++++++
+ tests/test_idna.py | 24 ++++++++++++++++++++++++
+ 2 files changed, 35 insertions(+)
+
+diff --git a/idna/core.py b/idna/core.py
+index 4a9fc75..26bb9fa 100644
+--- a/idna/core.py
++++ b/idna/core.py
+@@ -230,6 +230,17 @@ def check_label(label: Union[str, bytes, bytearray]) -> None:
+         label = label.decode('utf-8')
+     if len(label) == 0:
+         raise IDNAError('Empty Label')
++    # Reject oversized labels before per-codepoint validation runs.
++    # CONTEXTJ/CONTEXTO checks scan the whole label per codepoint, so an
++    # uncapped label drives validation into quadratic time
++    # (GHSA-65pc-fj4g-8rjx / CVE-2024-3651). encode()/decode() cap the
++    # whole-domain length; this cap protects direct callers of
++    # alabel/ulabel/check_label and the idna2008 incremental codec.
++    # Use the whole-domain bound rather than the per-label DNS bound so
++    # that UTS #46 lenient decoding of labels longer than 63 chars is
++    # preserved.
++    if not valid_string_length(label, trailing_dot=True):
++        raise IDNAError("Label too long")
+ 
+     check_nfc(label)
+     check_hyphen_ok(label)
+diff --git a/tests/test_idna.py b/tests/test_idna.py
+index 5001b48..2dc0892 100755
+--- a/tests/test_idna.py
++++ b/tests/test_idna.py
+@@ -91,6 +91,30 @@ class IDNATests(unittest.TestCase):
+             self.assertRaises(idna.IDNAError, idna.decode, payload)
+             self.assertLess(time.perf_counter() - start, 1.0)
+ 
++    def test_oversized_label_rejected_promptly(self):
++        # The whole-domain cap in encode()/decode() does not cover direct
++        # callers of alabel/ulabel/check_label, nor the idna2008
++        # incremental codec which calls alabel/ulabel per label. Without a
++        # per-label cap, a single oversized CONTEXTO-heavy label still
++        # drives validation into quadratic time.
++        import codecs
++        import time
++
++        import idna.codec  # noqa: F401  (register the idna2008 codec)
++
++        payload = "・" * 8000 + "漢"
++        start = time.perf_counter()
++        self.assertRaises(idna.IDNAError, idna.check_label, payload)
++        self.assertRaises(idna.IDNAError, idna.alabel, payload)
++        self.assertRaises(idna.IDNAError, idna.ulabel, payload)
++        self.assertRaises(
++            idna.IDNAError,
++            codecs.getincrementalencoder("idna2008")().encode,
++            payload,
++            True,
++        )
++        self.assertLess(time.perf_counter() - start, 1.0)
++
+     def test_check_bidi(self):
+ 
+         l = '\u0061'
diff --git a/meta/recipes-devtools/python/python3-idna_3.7.bb b/meta/recipes-devtools/python/python3-idna_3.7.bb
index 729aff1c46..5322984a24 100644
--- a/meta/recipes-devtools/python/python3-idna_3.7.bb
+++ b/meta/recipes-devtools/python/python3-idna_3.7.bb
@@ -3,6 +3,11 @@ HOMEPAGE = "https://github.com/kjd/idna"
 LICENSE = "BSD-3-Clause & Python-2.0 & Unicode-TOU"
 LIC_FILES_CHKSUM = "file://LICENSE.md;md5=204c0612e40a4dd46012a78d02c80fb1"
 
+SRC_URI += " \
+    file://CVE-2026-45409_p1.patch \
+    file://CVE-2026-45409_p2.patch \
+    file://CVE-2026-45409_p3.patch \
+"
 SRC_URI[sha256sum] = "028ff3aadf0609c1fd278d8ea3089299412a7a8b9bd005dd08b9f8285bcb5cfc"
 
 inherit pypi python_flit_core
-- 
2.35.6