diff --git a/version.go b/version.go
index ff499fb..304edc3 100644
--- a/version.go
+++ b/version.go
@@ -39,9 +39,11 @@ var (
 )
 
 // semVerRegex is the regular expression used to parse a semantic version.
-const semVerRegex string = `v?([0-9]+)(\.[0-9]+)?(\.[0-9]+)?` +
-	`(-([0-9A-Za-z\-]+(\.[0-9A-Za-z\-]+)*))?` +
-	`(\+([0-9A-Za-z\-]+(\.[0-9A-Za-z\-]+)*))?`
+// This is not the official regex from the semver spec. It has been modified to allow for loose handling
+// where versions like 2.1 are detected.
+const semVerRegex string = `v?(0|[1-9]\d*)(?:\.(0|[1-9]\d*))?(?:\.(0|[1-9]\d*))?` +
+	`(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?` +
+	`(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?`
 
 // Version represents a single semantic version.
 type Version struct {
@@ -146,8 +148,8 @@ func NewVersion(v string) (*Version, error) {
 	}
 
 	sv := &Version{
-		metadata: m[8],
-		pre:      m[5],
+		metadata: m[5],
+		pre:      m[4],
 		original: v,
 	}
 
@@ -158,7 +160,7 @@ func NewVersion(v string) (*Version, error) {
 	}
 
 	if m[2] != "" {
-		sv.minor, err = strconv.ParseUint(strings.TrimPrefix(m[2], "."), 10, 64)
+		sv.minor, err = strconv.ParseUint(m[2], 10, 64)
 		if err != nil {
 			return nil, fmt.Errorf("Error parsing version segment: %s", err)
 		}
@@ -167,7 +169,7 @@ func NewVersion(v string) (*Version, error) {
 	}
 
 	if m[3] != "" {
-		sv.patch, err = strconv.ParseUint(strings.TrimPrefix(m[3], "."), 10, 64)
+		sv.patch, err = strconv.ParseUint(m[3], 10, 64)
 		if err != nil {
 			return nil, fmt.Errorf("Error parsing version segment: %s", err)
 		}
@@ -612,7 +614,9 @@ func containsOnly(s string, comp string) bool {
 func validatePrerelease(p string) error {
 	eparts := strings.Split(p, ".")
 	for _, p := range eparts {
-		if containsOnly(p, num) {
+		if p == "" {
+			return ErrInvalidMetadata
+		} else if containsOnly(p, num) {
 			if len(p) > 1 && p[0] == '0' {
 				return ErrSegmentStartsZero
 			}
@@ -631,7 +635,9 @@ func validatePrerelease(p string) error {
 func validateMetadata(m string) error {
 	eparts := strings.Split(m, ".")
 	for _, p := range eparts {
-		if !containsOnly(p, allowed) {
+		if p == "" {
+			return ErrInvalidMetadata
+		} else if !containsOnly(p, allowed) {
 			return ErrInvalidMetadata
 		}
 	}
diff --git a/version_test.go b/version_test.go
index 74a1e91..2899598 100644
--- a/version_test.go
+++ b/version_test.go
@@ -21,6 +21,7 @@ func TestStrictNewVersion(t *testing.T) {
 		{"v1.0", true},
 		{"1", true},
 		{"v1", true},
+		{"1.2", true},
 		{"1.2.beta", true},
 		{"v1.2.beta", true},
 		{"foo", true},
@@ -45,6 +46,25 @@ func TestStrictNewVersion(t *testing.T) {
 		// The SemVer spec in a pre-release expects to allow [0-9A-Za-z-]. But,
 		// the lack of all 3 parts in this version should produce an error.
 		{"20221209-update-renovatejson-v4", true},
+
+		// Various cases that are invalid semver
+		{"1.1.2+.123", true},                             // A leading . in build metadata. This would signify that the first segment is empty
+		{"1.0.0-alpha_beta", true},                       // An underscore in the pre-release is an invalid character
+		{"1.0.0-alpha..", true},                          // Multiple empty segments
+		{"1.0.0-alpha..1", true},                         // Multiple empty segments but one with a value
+		{"01.1.1", true},                                 // A leading 0 on a number segment
+		{"1.01.1", true},                                 // A leading 0 on a number segment
+		{"1.1.01", true},                                 // A leading 0 on a number segment
+		{"9.8.7+meta+meta", true},                        // Multiple metadata parts
+		{"1.2.31----RC-SNAPSHOT.12.09.1--.12+788", true}, // Leading 0 in a number part of a pre-release segment
+		{"1.2.3-0123", true},
+		{"1.2.3-0123.0123", true},
+		{"+invalid", true},
+		{"-invalid", true},
+		{"-invalid.01", true},
+		{"alpha+beta", true},
+		{"1.2.3-alpha_beta+foo", true},
+		{"1.0.0-alpha..1", true},
 	}
 
 	for _, tc := range tests {
@@ -101,6 +121,17 @@ func TestNewVersion(t *testing.T) {
 
 		// The SemVer spec in a pre-release expects to allow [0-9A-Za-z-].
 		{"20221209-update-renovatejson-v4", false},
+
+		// Various cases that are invalid semver
+		{"1.1.2+.123", true},                             // A leading . in build metadata. This would signify that the first segment is empty
+		{"1.0.0-alpha_beta", true},                       // An underscore in the pre-release is an invalid character
+		{"1.0.0-alpha..", true},                          // Multiple empty segments
+		{"1.0.0-alpha..1", true},                         // Multiple empty segments but one with a value
+		{"01.1.1", true},                                 // A leading 0 on a number segment
+		{"1.01.1", true},                                 // A leading 0 on a number segment
+		{"1.1.01", true},                                 // A leading 0 on a number segment
+		{"9.8.7+meta+meta", true},                        // Multiple metadata parts
+		{"1.2.31----RC-SNAPSHOT.12.09.1--.12+788", true}, // Leading 0 in a number part of a pre-release segment
 	}
 
 	for _, tc := range tests {