diff --git a/crates/matrix-sdk-crypto/RUSTSEC-0000-0000.md b/crates/matrix-sdk-crypto/RUSTSEC-0000-0000.md
new file mode 100644
index 0000000..5d36dba
--- /dev/null
+++ b/crates/matrix-sdk-crypto/RUSTSEC-0000-0000.md
@@ -0,0 +1,19 @@
+```toml
+[advisory]
+id = "RUSTSEC-0000-0000"
+package = "matrix-sdk-crypto"
+date = "2022-09-29"
+url = "https://github.com/matrix-org/matrix-rust-sdk/commit/093fb5d0aa21c0b5eaea6ec96b477f1075271cbb"
+references = ["https://github.com/matrix-org/matrix-rust-sdk/commit/41449d2cc360e347f5d4e1c154ec1e3185f11acd"]
+aliases = ["CVE-2022-39252", "GHSA-vp68-2wrm-69qm"]
+cvss = "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
+
+[versions]
+patched = [">= 0.6.0"]
+```
+
+# matrix-sdk Impersonation of room keys
+
+When the user receives a forwarded room key, the software accepts it without
+checking who the room key came from. This allows homeservers to try to insert
+room keys of questionable validity, potentially mounting an impersonation attack.