Provide references for CVE-2021-43854.
Where can I find more information about CVE-2021-43854?
References are available at: https://github.com/nltk/nltk/security/advisories/GHSA-f8m6-h2c7-8h9x, https://github.com/nltk/nltk/issues/2866, https://github.com/nltk/nltk/pull/2869, https://github.com/nltk/nltk/commit/1405aad979c6b8080dbbc8e0858f89b2e3690341.