diff --git a/src/check_cve/check.py b/src/check_cve/check.py
index 25a8fab..ac27a0f 100755
--- a/src/check_cve/check.py
+++ b/src/check_cve/check.py
@@ -61,7 +61,7 @@ def is_vulnerable(host, retries=2, timeout=10):
 
     logging.debug(f"Response status: {response.status}")
 
-    decoded_data = response.data.decode()
+    decoded_data = response.data.decode("utf-8", errors="ignore")
     logging.debug(f"Data:\n{decoded_data}")
 
     return INSECURE_CONTENT in decoded_data

UnicodeDecodeError: 'utf-8' codec can't decode byte 0xf6 in position 1144: invalid start byte
# 🐛 Bug Report



```console
$ cve-2019-19781 citrix.beispiel.de
Traceback (most recent call last):
  File "/home/ehret/.local/bin/cve-2019-19781", line 11, in <module>
    load_entry_point('cve-2019-19781', 'console_scripts', 'cve-2019-19781')()
  File "/tmp/check-cve-2019-19781/src/check_cve/check.py", line 117, in main
    if is_vulnerable(host, retries, timeout):
  File "/tmp/check-cve-2019-19781/src/check_cve/check.py", line 64, in is_vulnerable
    decoded_data = response.data.decode()
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xf6 in position 1144: invalid start byte
```

diff --git a/tests/test_check_cve.py b/tests/test_check_cve.py
index 8919e0c..d922e5d 100644
--- a/tests/test_check_cve.py
+++ b/tests/test_check_cve.py
@@ -128,3 +128,16 @@ def test_non_vuln_host():
             mock_lib.PoolManager().request().status = 403
             return_code = check_cve.check.main()
             assert return_code == 0, "main() should return success"
+
+
+def test_non_utf8_response():
+    """Verify the utility handles responses containing invalid utf-8 data."""
+    # Hebrew string saying "forged"
+    bogus = "מזויף means bogus"
+    bogus_iso_8859_8 = bogus.encode("iso-8859-8")
+    with patch.object(sys, "argv", ["exe_name", "--log-level=debug", "github.com"]):
+        with patch("check_cve.check.urllib3") as mock_lib:
+            mock_lib.PoolManager().request().data = bogus_iso_8859_8
+            mock_lib.PoolManager().request().status = 403
+            return_code = check_cve.check.main()
+            assert return_code == 0, "main() should return success"

pip install -e .[dev]
parse_log_pytest
requirements.txt
pytest pytest-cov pytest-xdist pytest-mock pytest-asyncio
apt-get update apt-get install -y gcc
3.9
requirements.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
coverage==7.8.0
-e git+https://github.com/cisagov/check-cve-2019-19781.git@4142e02b96a537a4be5d367d564e242d9e8d3a84#egg=cve_2019_19781
docopt==0.6.2
exceptiongroup==1.2.2
execnet==2.1.1
iniconfig==2.1.0
packaging==24.2
pluggy==1.5.0
pytest==8.3.5
pytest-asyncio==0.26.0
pytest-cov==6.0.0
pytest-mock==3.14.0
pytest-xdist==3.6.1
schema==0.7.7
tomli==2.2.1
typing_extensions==4.13.0
urllib3==2.3.0

name: check-cve-2019-19781
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.4.4=h6a678d5_1
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=3.0.16=h5eee18b_0
  - pip=25.0=py39h06a4308_0
  - python=3.9.21=he870216_1
  - readline=8.2=h5eee18b_0
  - setuptools=75.8.0=py39h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - tzdata=2025a=h04d1e81_0
  - wheel=0.45.1=py39h06a4308_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - coverage==7.8.0
      - docopt==0.6.2
      - exceptiongroup==1.2.2
      - execnet==2.1.1
      - iniconfig==2.1.0
      - packaging==24.2
      - pluggy==1.5.0
      - pytest==8.3.5
      - pytest-asyncio==0.26.0
      - pytest-cov==6.0.0
      - pytest-mock==3.14.0
      - pytest-xdist==3.6.1
      - schema==0.7.7
      - tomli==2.2.1
      - typing-extensions==4.13.0
      - urllib3==2.3.0
prefix: /opt/conda/envs/check-cve-2019-19781

tests/test_check_cve.py::test_non_utf8_response
tests/test_check_cve.py::test_stdout_version tests/test_check_cve.py::test_log_levels[debug] tests/test_check_cve.py::test_log_levels[info] tests/test_check_cve.py::test_log_levels[warning] tests/test_check_cve.py::test_log_levels[error] tests/test_check_cve.py::test_log_levels[critical] tests/test_check_cve.py::test_missing_host_arg tests/test_check_cve.py::test_connection_error tests/test_check_cve.py::test_valid_timeout tests/test_check_cve.py::test_invalid_timeout tests/test_check_cve.py::test_valid_retries tests/test_check_cve.py::test_invalid_retries tests/test_check_cve.py::test_vuln_host tests/test_check_cve.py::test_non_vuln_host
src/check_cve/check.py
src/check_cve/check.py