diff --git a/pyproject.toml b/pyproject.toml
index 4d111a21..81ac2211 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -27,7 +27,7 @@ dependencies = [
     "anthropic>=0.108",  # claude-fable-5 support; hard runtime floor is 0.105 (mid-conversation system blocks)
     "httpx>=0.28",
     "mcp>=1.27,<2",  # v2 is a breaking rewrite (2.0.0a1 live 2026-06-11; stable ~2026-07-27) — streamablehttp_client removed, 2-tuple transport, snake_case types; migrate deliberately
-    "starlette>=1.0.1",  # PYSEC-2026-161: host-header path-injection in URL reconstruction (auth-bypass on apps comparing reconstructed URL paths)
+    "starlette>=1.3.1",  # CVE-2026-54282 (path->authority host spoof) + CVE-2026-54283 (url-encoded form DoS); supersedes the PYSEC-2026-161 host-header path-injection floor
     "uvicorn>=0.34",
     "sse-starlette>=2.0",
     "httpx-sse>=0.4",
@@ -39,7 +39,7 @@ dependencies = [
     "structlog>=24.1",
     "PyJWT>=2.8",
     "bcrypt>=4.0",
-    "cryptography>=42",
+    "cryptography>=48.0.1",  # GHSA-537c-gmf6-5ccf: PyPI wheels <48.0.1 bundle a vulnerable statically-linked OpenSSL (2026-06-09 secadv)
     "lacme>=1.0.5",
     "python-frontmatter>=1.0",
     "pypdfium2>=4",  # PDF text-extract + rasterize for models without native PDF input (core/pdf.py)
diff --git a/uv.lock b/uv.lock
index 1a9dd4ec..ff294f0f 100644
--- a/uv.lock
+++ b/uv.lock
@@ -2495,7 +2495,7 @@ requires-dist = [
     { name = "anthropic", specifier = ">=0.108" },
     { name = "bcrypt", specifier = ">=4.0" },
     { name = "croniter", specifier = ">=3.0" },
-    { name = "cryptography", specifier = ">=42" },
+    { name = "cryptography", specifier = ">=48.0.1" },
     { name = "discord-py", marker = "extra == 'discord'", specifier = ">=2.4" },
     { name = "httpx", specifier = ">=0.28" },
     { name = "httpx-sse", specifier = ">=0.4" },
@@ -2516,7 +2516,7 @@ requires-dist = [
     { name = "slack-bolt", marker = "extra == 'test'", specifier = ">=1.18" },
     { name = "sqlalchemy", specifier = ">=2.0" },
     { name = "sse-starlette", specifier = ">=2.0" },
-    { name = "starlette", specifier = ">=1.0.1" },
+    { name = "starlette", specifier = ">=1.3.1" },
     { name = "structlog", specifier = ">=24.1" },
     { name = "turnstone", extras = ["discord", "slack"], marker = "extra == 'all'" },
     { name = "uvicorn", specifier = ">=0.34" },