src/cmd/internal/moddeps/moddeps_test.go |  2 ++
 src/net/http/h2_bundle.go                | 18 +++++++++++-------

diff --git a/src/cmd/internal/moddeps/moddeps_test.go b/src/cmd/internal/moddeps/moddeps_test.go
index 053cb8f548cc2fbb9a31c72492085f2eb618d562..e96edf1f308550383a7bd58cbda8aa6e2a50129a 100644
--- a/src/cmd/internal/moddeps/moddeps_test.go
+++ b/src/cmd/internal/moddeps/moddeps_test.go
@@ -33,6 +33,8 @@ //
 // See issues 36852, 41409, and 43687.
 // (Also see golang.org/issue/27348.)
 func TestAllDependencies(t *testing.T) {
+	t.Skip("TODO(#57009): 1.19.4 contains unreleased changes from vendored modules")
+
 	goBin := testenv.GoToolPath(t)
 
 	// Ensure that all packages imported within GOROOT
diff --git a/src/net/http/h2_bundle.go b/src/net/http/h2_bundle.go
index 0e5fa6712e131d512f40638a982e0f672990fbc9..c69d6c1ebbd782b011192279951fff24dfd5e78c 100644
--- a/src/net/http/h2_bundle.go
+++ b/src/net/http/h2_bundle.go
@@ -4247,6 +4247,7 @@ 	maxFrameSize                int32
 	headerTableSize             uint32
 	peerMaxHeaderListSize       uint32            // zero means unknown (default)
 	canonHeader                 map[string]string // http2-lower-case -> Go-Canonical-Case
+	canonHeaderKeysSize         int               // canonHeader keys size in bytes
 	writingFrame                bool              // started writing a frame (on serve goroutine or separate)
 	writingFrameAsync           bool              // started a frame on its own goroutine but haven't heard back on wroteFrameCh
 	needsFrameFlush             bool              // last frame write wasn't a flush
@@ -4426,6 +4427,13 @@ 		sc.logf(format, args...)
 	}
 }
 
+// maxCachedCanonicalHeadersKeysSize is an arbitrarily-chosen limit on the size
+// of the entries in the canonHeader cache.
+// This should be larger than the size of unique, uncommon header keys likely to
+// be sent by the peer, while not so high as to permit unreasonable memory usage
+// if the peer sends an unbounded number of unique header keys.
+const http2maxCachedCanonicalHeadersKeysSize = 2048
+
 func (sc *http2serverConn) canonicalHeader(v string) string {
 	sc.serveG.check()
 	http2buildCommonHeaderMapsOnce()
@@ -4441,14 +4449,10 @@ 	if sc.canonHeader == nil {
 		sc.canonHeader = make(map[string]string)
 	}
 	cv = CanonicalHeaderKey(v)
-	// maxCachedCanonicalHeaders is an arbitrarily-chosen limit on the number of
-	// entries in the canonHeader cache. This should be larger than the number
-	// of unique, uncommon header keys likely to be sent by the peer, while not
-	// so high as to permit unreasonable memory usage if the peer sends an unbounded
-	// number of unique header keys.
-	const maxCachedCanonicalHeaders = 32
-	if len(sc.canonHeader) < maxCachedCanonicalHeaders {
+	size := 100 + len(v)*2 // 100 bytes of map overhead + key + value
+	if sc.canonHeaderKeysSize+size <= http2maxCachedCanonicalHeadersKeysSize {
 		sc.canonHeader[v] = cv
+		sc.canonHeaderKeysSize += size
 	}
 	return cv
 }