add changelog and a warning for is_signature_valid on crl (#3861)
* add changelog and a warning
* document this properly
diff --git a/docs/x509/reference.rst b/docs/x509/reference.rst
index 47f7625..5e1c95c 100644
--- a/docs/x509/reference.rst
+++ b/docs/x509/reference.rst
@@ -567,6 +567,12 @@
.. versionadded:: 2.1
+ .. warning::
+
+ Checking the validity of the signature on the CRL is insufficient
+ to know if the CRL should be trusted. More details are available
+ in :rfc:`5280`.
+
Returns True if the CRL signature is correct for given public key,
False otherwise.