diff --git a/src/basic/glob-util.c b/src/basic/glob-util.c
index fd60a6eda2..802ca8c655 100644
--- a/src/basic/glob-util.c
+++ b/src/basic/glob-util.c
@@ -63,6 +63,8 @@ int glob_first(const char *path, char **ret_first) {
                 return k;
 
         if (ret_first) {
+                assert(g.gl_pathv && g.gl_pathv[0]);
+
                 char *first = strdup(g.gl_pathv[0]);
                 if (!first)
                         return log_oom_debug();
diff --git a/src/boot/efi/efi-string.c b/src/boot/efi/efi-string.c
index 4400591255..ffe8552453 100644
--- a/src/boot/efi/efi-string.c
+++ b/src/boot/efi/efi-string.c
@@ -544,9 +544,11 @@ static bool push_str(FormatContext *ctx, SpecifierContext *sp) {
         if (sp->wstr && sizeof(wchar_t) == sizeof(char16_t)) {
                 memcpy(ctx->buf + ctx->n, sp->wstr, sp->len * sizeof(*sp->wstr));
                 ctx->n += sp->len;
-        } else
+        } else {
+                assert(sp->str || sp->wstr);
                 for (size_t i = 0; i < sp->len; i++)
                         ctx->buf[ctx->n++] = sp->str ? sp->str[i] : sp->wstr[i];
+        }
 
         if (sp->align_left)
                 push_padding(ctx, ' ', sp->padded_len);
diff --git a/src/busctl/busctl.c b/src/busctl/busctl.c
index 72eed36335..c1a0479015 100644
--- a/src/busctl/busctl.c
+++ b/src/busctl/busctl.c
@@ -1627,8 +1627,11 @@ static int message_append_cmdline(sd_bus_message *m, const char *signature, char
                         p--;
 
                         r = signature_element_length(signature, &k);
-                        if (r < 0)
+                        if (r < 0 || k < 2) {
+                                if (r >= 0 && k < 2)
+                                        r = -ERANGE;
                                 return log_error_errno(r, "Invalid struct/dict entry signature: %m");
+                        }
 
                         {
                                 char s[k-1];
diff --git a/src/libsystemd/sd-bus/bus-message.c b/src/libsystemd/sd-bus/bus-message.c
index 3cf1419a14..f1cf6a8cc4 100644
--- a/src/libsystemd/sd-bus/bus-message.c
+++ b/src/libsystemd/sd-bus/bus-message.c
@@ -2027,6 +2027,8 @@ _public_ int sd_bus_message_appendv(
                         r = signature_element_length(t, &k);
                         if (r < 0)
                                 return r;
+                        if (k < 2)
+                                return -ERANGE;
 
                         {
                                 char s[k - 1];
@@ -3470,6 +3472,8 @@ _public_ int sd_bus_message_readv(
                         r = signature_element_length(t, &k);
                         if (r < 0)
                                 return r;
+                        if (k < 2)
+                                return -ERANGE;
 
                         {
                                 char s[k - 1];
@@ -3650,6 +3654,8 @@ _public_ int sd_bus_message_skip(sd_bus_message *m, const char *types) {
                 r = signature_element_length(types, &k);
                 if (r < 0)
                         return r;
+                if (k < 2)
+                        return -ERANGE;
 
                 {
                         char s[k-1];