Pylint before 2.6.1 is susceptible to a Regular Expression Denial of Service (ReDoS) vulnerability due to issues in its pyreverse component. This issue arises from certain regular expressions in pyreverse that can be exploited by causing catastrophic backtracking, significantly slowing down the service by forcing it to take a disproportionate amount of time to process inputs. This vulnerability allows attackers to use specially crafted inputs that increase the processing time exponentially, potentially leading to a service becoming inaccessible to legitimate users.
https://github.com/pylint-dev/pylint/commit/5405dd5115d598fa69e49538d50ec79202b1b52e

Pylint 2.13.0 fixes a crash when using the doc_params extension.
https://github.com/PyCQA/pylint/issues/5322

Pylint 2.7.0 includes a fix for vulnerable regular expressions in 'pyreverse'.
https://github.com/pylint-dev/pylint/commit/5405dd5115d598fa69e49538d50ec79202b1b52e

Pylint 2.5.0 no longer allows ``python -m pylint ...`` to import user code. Previously, it added the current working directory as the first element of ``sys.path``. This opened up a potential security hole where ``pylint`` would import user level code as long as that code resided in modules having the same name as stdlib or pylint's own modules.