diff --git a/crates/openssl/RUSTSEC-0000-0000.md b/crates/openssl/RUSTSEC-0000-0000.md
new file mode 100644
index 0000000..1601ab9
--- /dev/null
+++ b/crates/openssl/RUSTSEC-0000-0000.md
@@ -0,0 +1,22 @@
+```toml
+[advisory]
+id = "RUSTSEC-0000-0000"
+package = "openssl"
+date = "2023-03-24"
+url = "https://github.com/sfackler/rust-openssl/pull/1854"
+categories = ["thread-safety"]
+
+[affected]
+functions = { "openssl::x509::X509NameBuilder::build" = ["< 0.10.48, >=0.9.7"] }
+
+[versions]
+patched = [">= 0.10.48"]
+```
+
+# `openssl` `X509NameBuilder::build` returned object is not thread safe
+
+OpenSSL has a `modified` bit that it can set on on `X509_NAME` objects. If this
+bit is set then the object is not thread-safe even when it appears the code is
+not modifying the value.
+
+Thanks to David Benjamin (Google) for reporting this issue.