From 188383b78dca13dfba769cac685ed7fe462f1002 Mon Sep 17 00:00:00 2001
From: Cristian Ramirez <62491943+Str0k@users.noreply.github.com>
Date: Fri, 11 Sep 2026 22:41:43 -0500
Subject: [PATCH] Reject non-ASCII digits and trailing newlines in version
 parsing

Co-authored-by: Codex <noreply@openai.com>
---
 changelog.d/pr478.bugfix.rst |  3 +++
 src/semver/version.py        |  6 +++---
 tests/test_strict_parsing.py | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 39 insertions(+), 3 deletions(-)
 create mode 100644 changelog.d/pr478.bugfix.rst
 create mode 100644 tests/test_strict_parsing.py

diff --git a/changelog.d/pr478.bugfix.rst b/changelog.d/pr478.bugfix.rst
new file mode 100644
index 00000000..87de2218
--- /dev/null
+++ b/changelog.d/pr478.bugfix.rst
@@ -0,0 +1,3 @@
+``Version.parse()`` and ``Version.is_valid()`` now reject non-ASCII digits and
+trailing newlines, in accordance with the SemVer grammar. Optional minor and
+patch parsing applies the same character restrictions.
diff --git a/src/semver/version.py b/src/semver/version.py
index 6fef00bc..0cfd2131 100644
--- a/src/semver/version.py
+++ b/src/semver/version.py
@@ -108,17 +108,17 @@ class Version:
                 [0-9a-zA-Z-]+
                 (?:\.[0-9a-zA-Z-]+)*
             ))?
-            $
+            \Z
         """
     #: Regex for a semver version
     _REGEX: ClassVar[Pattern[str]] = re.compile(
         _REGEX_TEMPLATE.format(opt_patch="", opt_minor=""),
-        re.VERBOSE,
+        re.VERBOSE | re.ASCII,
     )
     #: Regex for a semver version that might be shorter
     _REGEX_OPTIONAL_MINOR_AND_PATCH: ClassVar[Pattern[str]] = re.compile(
         _REGEX_TEMPLATE.format(opt_patch="?", opt_minor="?"),
-        re.VERBOSE,
+        re.VERBOSE | re.ASCII,
     )
 
     def __init__(
diff --git a/tests/test_strict_parsing.py b/tests/test_strict_parsing.py
new file mode 100644
index 00000000..b50bf5d1
--- /dev/null
+++ b/tests/test_strict_parsing.py
@@ -0,0 +1,33 @@
+import pytest
+
+from semver import Version
+
+
+@pytest.mark.parametrize(
+    "version",
+    [
+        "1.2.3\n",
+        "1.2.3-rc.1\n",
+        "1.2.3+build.1\n",
+        "1\u0662.2.3",
+        "1.2\u0663.3",
+        "1.2.3\u0664",
+        "1.2.3-1\u0662",
+        "1.2.3-\u0661alpha",
+    ],
+)
+@pytest.mark.parametrize("optional_minor_and_patch", [False, True])
+def test_parse_rejects_non_semver_characters(version, optional_minor_and_patch):
+    with pytest.raises(ValueError):
+        Version.parse(version, optional_minor_and_patch=optional_minor_and_patch)
+
+
+@pytest.mark.parametrize("version", ["1\n", "1.2\n", "1\u0662", "1.2\u0663"])
+def test_optional_parse_rejects_non_semver_characters(version):
+    with pytest.raises(ValueError):
+        Version.parse(version, optional_minor_and_patch=True)
+
+
+@pytest.mark.parametrize("version", ["1.2.3\n", "1\u0662.2.3", "1.2.3-\u0661alpha"])
+def test_is_valid_rejects_non_semver_characters(version):
+    assert not Version.is_valid(version)