diff --git a/commit-graph.c b/commit-graph.c
index ee66098e07..acac9bf6e1 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -275,68 +275,37 @@ struct commit_graph *load_commit_graph_one_fd_st(struct repository *r,
 	return ret;
 }
 
-static int verify_commit_graph_lite(struct commit_graph *g)
+static int graph_read_oid_fanout(const unsigned char *chunk_start,
+				 size_t chunk_size, void *data)
 {
+	struct commit_graph *g = data;
 	int i;
 
-	/*
-	 * Basic validation shared between parse_commit_graph()
-	 * which'll be called every time the graph is used, and the
-	 * much more expensive verify_commit_graph() used by
-	 * "commit-graph verify".
-	 *
-	 * There should only be very basic checks here to ensure that
-	 * we don't e.g. segfault in fill_commit_in_graph(), but
-	 * because this is a very hot codepath nothing that e.g. loops
-	 * over g->num_commits, or runs a checksum on the commit-graph
-	 * itself.
-	 */
-	if (!g->chunk_oid_fanout) {
-		error("commit-graph is missing the OID Fanout chunk");
-		return 1;
-	}
-	if (!g->chunk_oid_lookup) {
-		error("commit-graph is missing the OID Lookup chunk");
-		return 1;
-	}
-	if (!g->chunk_commit_data) {
-		error("commit-graph is missing the Commit Data chunk");
-		return 1;
-	}
+	if (chunk_size != 256 * sizeof(uint32_t))
+		return error(_("commit-graph oid fanout chunk is wrong size"));
+	g->chunk_oid_fanout = (const uint32_t *)chunk_start;
+	g->num_commits = ntohl(g->chunk_oid_fanout[255]);
 
 	for (i = 0; i < 255; i++) {
 		uint32_t oid_fanout1 = ntohl(g->chunk_oid_fanout[i]);
 		uint32_t oid_fanout2 = ntohl(g->chunk_oid_fanout[i + 1]);
 
 		if (oid_fanout1 > oid_fanout2) {
-			error("commit-graph fanout values out of order");
+			error(_("commit-graph fanout values out of order"));
 			return 1;
 		}
 	}
-	if (ntohl(g->chunk_oid_fanout[255]) != g->num_commits) {
-		error("commit-graph oid table and fanout disagree on size");
-		return 1;
-	}
 
 	return 0;
 }
 
-static int graph_read_oid_fanout(const unsigned char *chunk_start,
-				 size_t chunk_size, void *data)
-{
-	struct commit_graph *g = data;
-	if (chunk_size != 256 * sizeof(uint32_t))
-		return error("commit-graph oid fanout chunk is wrong size");
-	g->chunk_oid_fanout = (const uint32_t *)chunk_start;
-	return 0;
-}
-
 static int graph_read_oid_lookup(const unsigned char *chunk_start,
 				 size_t chunk_size, void *data)
 {
 	struct commit_graph *g = data;
 	g->chunk_oid_lookup = chunk_start;
-	g->num_commits = chunk_size / g->hash_len;
+	if (chunk_size / g->hash_len != g->num_commits)
+		return error(_("commit-graph OID lookup chunk is the wrong size"));
 	return 0;
 }
 
@@ -344,8 +313,8 @@ static int graph_read_commit_data(const unsigned char *chunk_start,
 				  size_t chunk_size, void *data)
 {
 	struct commit_graph *g = data;
-	if (chunk_size != g->num_commits * GRAPH_DATA_WIDTH)
-		return error("commit-graph commit data chunk is wrong size");
+	if (chunk_size / GRAPH_DATA_WIDTH != g->num_commits)
+		return error(_("commit-graph commit data chunk is wrong size"));
 	g->chunk_commit_data = chunk_start;
 	return 0;
 }
@@ -354,8 +323,8 @@ static int graph_read_generation_data(const unsigned char *chunk_start,
 				      size_t chunk_size, void *data)
 {
 	struct commit_graph *g = data;
-	if (chunk_size != g->num_commits * sizeof(uint32_t))
-		return error("commit-graph generations chunk is wrong size");
+	if (chunk_size / sizeof(uint32_t) != g->num_commits)
+		return error(_("commit-graph generations chunk is wrong size"));
 	g->chunk_generation_data = chunk_start;
 	return 0;
 }
@@ -364,8 +333,8 @@ static int graph_read_bloom_index(const unsigned char *chunk_start,
 				  size_t chunk_size, void *data)
 {
 	struct commit_graph *g = data;
-	if (chunk_size != g->num_commits * 4) {
-		warning("commit-graph changed-path index chunk is too small");
+	if (chunk_size / 4 != g->num_commits) {
+		warning(_("commit-graph changed-path index chunk is too small"));
 		return -1;
 	}
 	g->chunk_bloom_indexes = chunk_start;
@@ -379,8 +348,8 @@ static int graph_read_bloom_data(const unsigned char *chunk_start,
 	uint32_t hash_version;
 
 	if (chunk_size < BLOOMDATA_CHUNK_HEADER_SIZE) {
-		warning("ignoring too-small changed-path chunk"
-			" (%"PRIuMAX" < %"PRIuMAX") in commit-graph file",
+		warning(_("ignoring too-small changed-path chunk"
+			" (%"PRIuMAX" < %"PRIuMAX") in commit-graph file"),
 			(uintmax_t)chunk_size,
 			(uintmax_t)BLOOMDATA_CHUNK_HEADER_SIZE);
 		return -1;
@@ -462,9 +431,19 @@ struct commit_graph *parse_commit_graph(struct repo_settings *s,
 				   GRAPH_HEADER_SIZE, graph->num_chunks, 1))
 		goto free_and_return;
 
-	read_chunk(cf, GRAPH_CHUNKID_OIDFANOUT, graph_read_oid_fanout, graph);
-	read_chunk(cf, GRAPH_CHUNKID_OIDLOOKUP, graph_read_oid_lookup, graph);
-	read_chunk(cf, GRAPH_CHUNKID_DATA, graph_read_commit_data, graph);
+	if (read_chunk(cf, GRAPH_CHUNKID_OIDFANOUT, graph_read_oid_fanout, graph)) {
+		error(_("commit-graph required OID fanout chunk missing or corrupted"));
+		goto free_and_return;
+	}
+	if (read_chunk(cf, GRAPH_CHUNKID_OIDLOOKUP, graph_read_oid_lookup, graph)) {
+		error(_("commit-graph required OID lookup chunk missing or corrupted"));
+		goto free_and_return;
+	}
+	if (read_chunk(cf, GRAPH_CHUNKID_DATA, graph_read_commit_data, graph)) {
+		error(_("commit-graph required commit data chunk missing or corrupted"));
+		goto free_and_return;
+	}
+
 	pair_chunk(cf, GRAPH_CHUNKID_EXTRAEDGES, &graph->chunk_extra_edges,
 		   &graph->chunk_extra_edges_size);
 	pair_chunk(cf, GRAPH_CHUNKID_BASE, &graph->chunk_base_graphs,
@@ -499,9 +478,6 @@ struct commit_graph *parse_commit_graph(struct repo_settings *s,
 
 	oidread(&graph->oid, graph->data + graph->data_len - graph->hash_len);
 
-	if (verify_commit_graph_lite(graph))
-		goto free_and_return;
-
 	free_chunkfile(cf);
 	return graph;
 
@@ -629,7 +605,7 @@ int open_commit_graph_chain(const char *chain_file,
 			/* treat empty files the same as missing */
 			errno = ENOENT;
 		} else {
-			warning("commit-graph chain file too small");
+			warning(_("commit-graph chain file too small"));
 			errno = EINVAL;
 		}
 		return 0;
@@ -970,7 +946,7 @@ static int fill_commit_in_graph(struct repository *r,
 	parent_data_pos = edge_value & GRAPH_EDGE_LAST_MASK;
 	do {
 		if (g->chunk_extra_edges_size / sizeof(uint32_t) <= parent_data_pos) {
-			error("commit-graph extra-edges pointer out of bounds");
+			error(_("commit-graph extra-edges pointer out of bounds"));
 			free_commit_list(item->parents);
 			item->parents = NULL;
 			item->object.parsed = 0;
@@ -2690,10 +2666,6 @@ static int verify_one_commit_graph(struct repository *r,
 	struct commit *seen_gen_zero = NULL;
 	struct commit *seen_gen_non_zero = NULL;
 
-	verify_commit_graph_error = verify_commit_graph_lite(g);
-	if (verify_commit_graph_error)
-		return verify_commit_graph_error;
-
 	if (!commit_graph_checksum_valid(g)) {
 		graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
 		verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
diff --git a/midx.c b/midx.c
index 2f3863c936..1d14661dad 100644
--- a/midx.c
+++ b/midx.c
@@ -64,6 +64,7 @@ void get_midx_rev_filename(struct strbuf *out, struct multi_pack_index *m)
 static int midx_read_oid_fanout(const unsigned char *chunk_start,
 				size_t chunk_size, void *data)
 {
+	int i;
 	struct multi_pack_index *m = data;
 	m->chunk_oid_fanout = (uint32_t *)chunk_start;
 
@@ -71,6 +72,16 @@ static int midx_read_oid_fanout(const unsigned char *chunk_start,
 		error(_("multi-pack-index OID fanout is of the wrong size"));
 		return 1;
 	}
+	for (i = 0; i < 255; i++) {
+		uint32_t oid_fanout1 = ntohl(m->chunk_oid_fanout[i]);
+		uint32_t oid_fanout2 = ntohl(m->chunk_oid_fanout[i+1]);
+
+		if (oid_fanout1 > oid_fanout2) {
+			error(_("oid fanout out of order: fanout[%d] = %"PRIx32" > %"PRIx32" = fanout[%d]"),
+			      i, oid_fanout1, oid_fanout2, i + 1);
+			return 1;
+		}
+	}
 	m->num_objects = ntohl(m->chunk_oid_fanout[255]);
 	return 0;
 }
@@ -1782,15 +1793,6 @@ int verify_midx_file(struct repository *r, const char *object_dir, unsigned flag
 	}
 	stop_progress(&progress);
 
-	for (i = 0; i < 255; i++) {
-		uint32_t oid_fanout1 = ntohl(m->chunk_oid_fanout[i]);
-		uint32_t oid_fanout2 = ntohl(m->chunk_oid_fanout[i + 1]);
-
-		if (oid_fanout1 > oid_fanout2)
-			midx_report(_("oid fanout out of order: fanout[%d] = %"PRIx32" > %"PRIx32" = fanout[%d]"),
-				    i, oid_fanout1, oid_fanout2, i + 1);
-	}
-
 	if (m->num_objects == 0) {
 		midx_report(_("the midx contains no oid"));
 		/*
diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index d4fc65e078..7fe7c72a87 100755
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -540,17 +540,17 @@ test_expect_success 'detect low chunk count' '
 
 test_expect_success 'detect missing OID fanout chunk' '
 	corrupt_graph_and_verify $GRAPH_BYTE_OID_FANOUT_ID "\0" \
-		"missing the OID Fanout chunk"
+		"commit-graph required OID fanout chunk missing or corrupted"
 '
 
 test_expect_success 'detect missing OID lookup chunk' '
 	corrupt_graph_and_verify $GRAPH_BYTE_OID_LOOKUP_ID "\0" \
-		"missing the OID Lookup chunk"
+		"commit-graph required OID lookup chunk missing or corrupted"
 '
 
 test_expect_success 'detect missing commit data chunk' '
 	corrupt_graph_and_verify $GRAPH_BYTE_COMMIT_DATA_ID "\0" \
-		"missing the Commit Data chunk"
+		"commit-graph required commit data chunk missing or corrupted"
 '
 
 test_expect_success 'detect incorrect fanout' '
@@ -560,7 +560,7 @@ test_expect_success 'detect incorrect fanout' '
 
 test_expect_success 'detect incorrect fanout final value' '
 	corrupt_graph_and_verify $GRAPH_BYTE_FANOUT2 "\01" \
-		"oid table and fanout disagree on size"
+		"OID lookup chunk is the wrong size"
 '
 
 test_expect_success 'detect incorrect OID order' '
@@ -842,7 +842,7 @@ test_expect_success 'reader notices too-small oid fanout chunk' '
 	check_corrupt_chunk OIDF clear $(printf "000000%02x" $(test_seq 250)) &&
 	cat >expect.err <<-\EOF &&
 	error: commit-graph oid fanout chunk is wrong size
-	error: commit-graph is missing the OID Fanout chunk
+	error: commit-graph required OID fanout chunk missing or corrupted
 	EOF
 	test_cmp expect.err err
 '
@@ -850,7 +850,8 @@ test_expect_success 'reader notices too-small oid fanout chunk' '
 test_expect_success 'reader notices fanout/lookup table mismatch' '
 	check_corrupt_chunk OIDF 1020 "FFFFFFFF" &&
 	cat >expect.err <<-\EOF &&
-	error: commit-graph oid table and fanout disagree on size
+	error: commit-graph OID lookup chunk is the wrong size
+	error: commit-graph required OID lookup chunk missing or corrupted
 	EOF
 	test_cmp expect.err err
 '
@@ -866,6 +867,7 @@ test_expect_success 'reader notices out-of-bounds fanout' '
 	check_corrupt_chunk OIDF 0 $(printf "%02x000000" $(test_seq 0 254)) &&
 	cat >expect.err <<-\EOF &&
 	error: commit-graph fanout values out of order
+	error: commit-graph required OID fanout chunk missing or corrupted
 	EOF
 	test_cmp expect.err err
 '
@@ -874,7 +876,7 @@ test_expect_success 'reader notices too-small commit data chunk' '
 	check_corrupt_chunk CDAT clear 00000000 &&
 	cat >expect.err <<-\EOF &&
 	error: commit-graph commit data chunk is wrong size
-	error: commit-graph is missing the Commit Data chunk
+	error: commit-graph required commit data chunk missing or corrupted
 	EOF
 	test_cmp expect.err err
 '
diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh
index c4c6060cee..c20aafe99a 100755
--- a/t/t5319-multi-pack-index.sh
+++ b/t/t5319-multi-pack-index.sh
@@ -1157,4 +1157,18 @@ test_expect_success 'reader notices too-small revindex chunk' '
 	test_cmp expect.err err
 '
 
+test_expect_success 'reader notices out-of-bounds fanout' '
+	# This is similar to the out-of-bounds fanout test in t5318. The values
+	# in adjacent entries should be large but not identical (they
+	# are used as hi/lo starts for a binary search, which would then abort
+	# immediately).
+	corrupt_chunk OIDF 0 $(printf "%02x000000" $(test_seq 0 254)) &&
+	test_must_fail git log 2>err &&
+	cat >expect <<-\EOF &&
+	error: oid fanout out of order: fanout[254] = fe000000 > 5c = fanout[255]
+	fatal: multi-pack-index required OID fanout chunk missing or corrupted
+	EOF
+	test_cmp expect err
+'
+
 test_done