diff --git a/docs/development/test-vectors.rst b/docs/development/test-vectors.rst
index ea44a46..d400e66 100644
--- a/docs/development/test-vectors.rst
+++ b/docs/development/test-vectors.rst
@@ -233,6 +233,8 @@
 * ``cp_user_notice_no_explicit_text.pem`` - An RSA 2048 bit self-signed
   certificate containing a certificate policies extension with a user notice
   with no explicit text.
+* ``cp_invalid.pem`` - An RSA 2048 bit self-signed certificate containing a
+  certificate policies extension with invalid data.
 * ``ian_uri.pem`` - An RSA 2048 bit certificate containing an issuer
   alternative name extension with a ``URI`` general name.
 * ``ocsp_nocheck.pem`` - An RSA 2048 bit self-signed certificate containing
diff --git a/vectors/cryptography_vectors/x509/custom/cp_invalid.pem b/vectors/cryptography_vectors/x509/custom/cp_invalid.pem
new file mode 100644
index 0000000..b7bcc07
--- /dev/null
+++ b/vectors/cryptography_vectors/x509/custom/cp_invalid.pem
@@ -0,0 +1,16 @@
+-----BEGIN CERTIFICATE-----
+MIIC8TCCAdmgAwIBAgITBmsoYWX1PCELRmm8qB2WJ2QdDjANBgkqhkiG9w0BAQUFADASMRAwDgYD
+VQQDDAdQeUNBIENBMB4XDTE1MDUxMTE4NTc0NVoXDTE2MDUxMDE4NTc0NVowEjEQMA4GA1UEAwwH
+UHlDQSBDQTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAK3FTRITEY4b/Y1Uv4CtH61Y
+19TPxK2+H/XuqHwtYlPRyD35LLFES0wykf0V2m1DUmf9jQa9R63jBZxzCgJ/oIJzV28PgSg9P/Nn
+417fNASDduY2GPvYuwwKXcLY2fBBFjBrz7z/5tyXCADjLDkzoUTzQlYPbhOrFU5QwaqlckXBgt/4
+8GRDujoHy4RSMEDNjLUDgwx7Z/JK2ujbGJDguLRuBsHirk2h6xXEmSWxquKDXw4NnakwBqp8kKhQ
+2xTSWXxabNps8FCBM4sC78gKgONy3lbYdHFt/2BU4yAMyowJwtDEYHCqe1g4sVsB839Ol0SXb6vl
+eXQ6dx+zbi8UzTsCAwEAAaNAMD4wPAYDVR0gBDUwMzAxBgtghkgB4DkBAgMEATAiMCAGCCsGAQUF
+BwICFhRodHRwOi8vb3RoZXIuY29tL2NwczANBgkqhkiG9w0BAQUFAAOCAQEADpZIjHvu02euPNI8
+nzzDufRXEnjrF09xc9pudxTjWU2mSVApXPmTDyWzOD+2HmsNKHRE6sWjca5qPDeDbGq4JOw+TzYq
+9eoqwK2Sh0QHUpg5ZaAmIJ1qe5/sNETH5RFlXrlzW9S0rwViLgUaJp6MreTdGZbxdpNsfdkuNd+S
+Tz0MA/3ScbdUcj6uwQQ4JxQiTuPwD35pKwxfUzHjeTmqIEHDuCk17KqIRORdbeD3vFx0R5IQ3mQ6
+9zSGY2AGB0A9oS0qQ2/Mh59A6xyjbPH3Rr7g5MW58PPTWp2FSXkloy7Ze+doQ7wXE6PVmaeKz5qA
+9OGaCHIiC2iG9UcqWxfeWw==
+-----END CERTIFICATE-----