diff --git a/powershell/ql/lib/semmle/code/powershell/security/UnsafeDeserializationCustomizations.qll b/powershell/ql/lib/semmle/code/powershell/security/UnsafeDeserializationCustomizations.qll
index 4615161364fb..f75ce4ade5e6 100644
--- a/powershell/ql/lib/semmle/code/powershell/security/UnsafeDeserializationCustomizations.qll
+++ b/powershell/ql/lib/semmle/code/powershell/security/UnsafeDeserializationCustomizations.qll
@@ -102,6 +102,31 @@ module UnsafeDeserialization {
     typeName = "system.resources.resxresourcereader"
   }
 
+  /**
+   * An argument to Import-Clixml or ConvertFrom-CliXml, which deserializes CLIXML
+   * and can trigger gadget chains leading to code execution.
+   */
+  class CliXmlDeserializationSink extends Sink {
+    string cmdletName;
+
+    CliXmlDeserializationSink() {
+      exists(DataFlow::CallNode call |
+        call.matchesName(cmdletName) and
+        (
+          this = call.getAnArgument()
+          or
+          this.asExpr().(CfgNodes::ExprNodes::PipelineArgumentCfgNode).getCall() =
+            call.getCallNode()
+        )
+      |
+        cmdletName = "Import-Clixml" or
+        cmdletName = "ConvertFrom-CliXml"
+      )
+    }
+
+    override string getSinkType() { result = "call to " + cmdletName }
+  }
+
   /**
    * A BinaryFormatter deserialization method call, including Deserialize, UnsafeDeserialize,
    * and UnsafeDeserializeMethodResponse.
diff --git a/powershell/ql/test/query-tests/security/cwe-502/UnsafeDeserialization.expected b/powershell/ql/test/query-tests/security/cwe-502/UnsafeDeserialization.expected
index 81aa06cc5d11..6eed3468d308 100644
--- a/powershell/ql/test/query-tests/security/cwe-502/UnsafeDeserialization.expected
+++ b/powershell/ql/test/query-tests/security/cwe-502/UnsafeDeserialization.expected
@@ -16,8 +16,11 @@
 | test.ps1:76:49:76:57 | stream15 | test.ps1:74:12:74:42 | Call to read-host | test.ps1:76:49:76:57 | stream15 | This unsafe deserializer deserializes  on a $@. | test.ps1:74:12:74:42 | Call to read-host | read from stdin |
 | test.ps1:81:40:81:47 | input16 | test.ps1:79:12:79:33 | Call to read-host | test.ps1:81:40:81:47 | input16 | This unsafe deserializer deserializes  on a $@. | test.ps1:79:12:79:33 | Call to read-host | read from stdin |
 | test.ps1:86:48:86:55 | bytes17 | test.ps1:84:12:84:40 | Call to read-host | test.ps1:86:48:86:55 | bytes17 | This unsafe deserializer deserializes  on a $@. | test.ps1:84:12:84:40 | Call to read-host | read from stdin |
-| test.ps1:98:39:98:49 | fileStream | test.ps1:96:14:96:58 | Call to readallbytes | test.ps1:98:39:98:49 | fileStream | This unsafe deserializer deserializes  on a $@. | test.ps1:96:14:96:58 | Call to readallbytes | file stream |
-| test.ps1:103:41:103:53 | remoteStream | test.ps1:101:16:101:92 | Call to downloaddata | test.ps1:103:41:103:53 | remoteStream | This unsafe deserializer deserializes  on a $@. | test.ps1:101:16:101:92 | Call to downloaddata | remote flow source |
+| test.ps1:90:30:90:37 | input18 | test.ps1:89:12:89:38 | Call to read-host | test.ps1:90:30:90:37 | input18 | This unsafe deserializer deserializes  on a $@. | test.ps1:89:12:89:38 | Call to read-host | read from stdin |
+| test.ps1:94:37:94:44 | input19 | test.ps1:93:12:93:41 | Call to read-host | test.ps1:94:37:94:44 | input19 | This unsafe deserializer deserializes  on a $@. | test.ps1:93:12:93:41 | Call to read-host | read from stdin |
+| test.ps1:98:10:98:17 | input20 | test.ps1:97:12:97:42 | Call to read-host | test.ps1:98:10:98:17 | input20 | This unsafe deserializer deserializes  on a $@. | test.ps1:97:12:97:42 | Call to read-host | read from stdin |
+| test.ps1:113:39:113:49 | fileStream | test.ps1:111:14:111:58 | Call to readallbytes | test.ps1:113:39:113:49 | fileStream | This unsafe deserializer deserializes  on a $@. | test.ps1:111:14:111:58 | Call to readallbytes | file stream |
+| test.ps1:118:41:118:53 | remoteStream | test.ps1:116:16:116:92 | Call to downloaddata | test.ps1:118:41:118:53 | remoteStream | This unsafe deserializer deserializes  on a $@. | test.ps1:116:16:116:92 | Call to downloaddata | remote flow source |
 edges
 | test.ps1:2:1:2:16 | untrustedBase64 | test.ps1:4:69:4:84 | untrustedBase64 | provenance |  |
 | test.ps1:2:20:2:47 | Call to read-host | test.ps1:2:1:2:16 | untrustedBase64 | provenance | Src:MaD:0  |
@@ -87,16 +90,22 @@ edges
 | test.ps1:85:1:85:8 | bytes17 | test.ps1:86:48:86:55 | bytes17 | provenance |  |
 | test.ps1:85:12:85:48 | Call to frombase64string | test.ps1:85:1:85:8 | bytes17 | provenance |  |
 | test.ps1:85:40:85:47 | input17 | test.ps1:85:12:85:48 | Call to frombase64string | provenance | MaD:142 |
-| test.ps1:96:1:96:10 | fileBytes | test.ps1:97:45:97:54 | fileBytes | provenance |  |
-| test.ps1:96:14:96:58 | Call to readallbytes | test.ps1:96:1:96:10 | fileBytes | provenance | Src:MaD:83  |
-| test.ps1:97:1:97:11 | fileStream | test.ps1:98:39:98:49 | fileStream | provenance |  |
-| test.ps1:97:15:97:55 | Call to new | test.ps1:97:1:97:11 | fileStream | provenance |  |
-| test.ps1:97:45:97:54 | fileBytes | test.ps1:97:15:97:55 | Call to new | provenance | MaD:104 |
-| test.ps1:101:1:101:12 | remoteBytes | test.ps1:102:47:102:58 | remoteBytes | provenance |  |
-| test.ps1:101:16:101:92 | Call to downloaddata | test.ps1:101:1:101:12 | remoteBytes | provenance | Src:MaD:125  |
-| test.ps1:102:1:102:13 | remoteStream | test.ps1:103:41:103:53 | remoteStream | provenance |  |
-| test.ps1:102:17:102:59 | Call to new | test.ps1:102:1:102:13 | remoteStream | provenance |  |
-| test.ps1:102:47:102:58 | remoteBytes | test.ps1:102:17:102:59 | Call to new | provenance | MaD:104 |
+| test.ps1:89:1:89:8 | input18 | test.ps1:90:30:90:37 | input18 | provenance |  |
+| test.ps1:89:12:89:38 | Call to read-host | test.ps1:89:1:89:8 | input18 | provenance | Src:MaD:0  |
+| test.ps1:93:1:93:8 | input19 | test.ps1:94:37:94:44 | input19 | provenance |  |
+| test.ps1:93:12:93:41 | Call to read-host | test.ps1:93:1:93:8 | input19 | provenance | Src:MaD:0  |
+| test.ps1:97:1:97:8 | input20 | test.ps1:98:10:98:17 | input20 | provenance |  |
+| test.ps1:97:12:97:42 | Call to read-host | test.ps1:97:1:97:8 | input20 | provenance | Src:MaD:0  |
+| test.ps1:111:1:111:10 | fileBytes | test.ps1:112:45:112:54 | fileBytes | provenance |  |
+| test.ps1:111:14:111:58 | Call to readallbytes | test.ps1:111:1:111:10 | fileBytes | provenance | Src:MaD:83  |
+| test.ps1:112:1:112:11 | fileStream | test.ps1:113:39:113:49 | fileStream | provenance |  |
+| test.ps1:112:15:112:55 | Call to new | test.ps1:112:1:112:11 | fileStream | provenance |  |
+| test.ps1:112:45:112:54 | fileBytes | test.ps1:112:15:112:55 | Call to new | provenance | MaD:104 |
+| test.ps1:116:1:116:12 | remoteBytes | test.ps1:117:47:117:58 | remoteBytes | provenance |  |
+| test.ps1:116:16:116:92 | Call to downloaddata | test.ps1:116:1:116:12 | remoteBytes | provenance | Src:MaD:125  |
+| test.ps1:117:1:117:13 | remoteStream | test.ps1:118:41:118:53 | remoteStream | provenance |  |
+| test.ps1:117:17:117:59 | Call to new | test.ps1:117:1:117:13 | remoteStream | provenance |  |
+| test.ps1:117:47:117:58 | remoteBytes | test.ps1:117:17:117:59 | Call to new | provenance | MaD:104 |
 nodes
 | test.ps1:2:1:2:16 | untrustedBase64 | semmle.label | untrustedBase64 |
 | test.ps1:2:20:2:47 | Call to read-host | semmle.label | Call to read-host |
@@ -183,16 +192,25 @@ nodes
 | test.ps1:85:12:85:48 | Call to frombase64string | semmle.label | Call to frombase64string |
 | test.ps1:85:40:85:47 | input17 | semmle.label | input17 |
 | test.ps1:86:48:86:55 | bytes17 | semmle.label | bytes17 |
-| test.ps1:96:1:96:10 | fileBytes | semmle.label | fileBytes |
-| test.ps1:96:14:96:58 | Call to readallbytes | semmle.label | Call to readallbytes |
-| test.ps1:97:1:97:11 | fileStream | semmle.label | fileStream |
-| test.ps1:97:15:97:55 | Call to new | semmle.label | Call to new |
-| test.ps1:97:45:97:54 | fileBytes | semmle.label | fileBytes |
-| test.ps1:98:39:98:49 | fileStream | semmle.label | fileStream |
-| test.ps1:101:1:101:12 | remoteBytes | semmle.label | remoteBytes |
-| test.ps1:101:16:101:92 | Call to downloaddata | semmle.label | Call to downloaddata |
-| test.ps1:102:1:102:13 | remoteStream | semmle.label | remoteStream |
-| test.ps1:102:17:102:59 | Call to new | semmle.label | Call to new |
-| test.ps1:102:47:102:58 | remoteBytes | semmle.label | remoteBytes |
-| test.ps1:103:41:103:53 | remoteStream | semmle.label | remoteStream |
+| test.ps1:89:1:89:8 | input18 | semmle.label | input18 |
+| test.ps1:89:12:89:38 | Call to read-host | semmle.label | Call to read-host |
+| test.ps1:90:30:90:37 | input18 | semmle.label | input18 |
+| test.ps1:93:1:93:8 | input19 | semmle.label | input19 |
+| test.ps1:93:12:93:41 | Call to read-host | semmle.label | Call to read-host |
+| test.ps1:94:37:94:44 | input19 | semmle.label | input19 |
+| test.ps1:97:1:97:8 | input20 | semmle.label | input20 |
+| test.ps1:97:12:97:42 | Call to read-host | semmle.label | Call to read-host |
+| test.ps1:98:10:98:17 | input20 | semmle.label | input20 |
+| test.ps1:111:1:111:10 | fileBytes | semmle.label | fileBytes |
+| test.ps1:111:14:111:58 | Call to readallbytes | semmle.label | Call to readallbytes |
+| test.ps1:112:1:112:11 | fileStream | semmle.label | fileStream |
+| test.ps1:112:15:112:55 | Call to new | semmle.label | Call to new |
+| test.ps1:112:45:112:54 | fileBytes | semmle.label | fileBytes |
+| test.ps1:113:39:113:49 | fileStream | semmle.label | fileStream |
+| test.ps1:116:1:116:12 | remoteBytes | semmle.label | remoteBytes |
+| test.ps1:116:16:116:92 | Call to downloaddata | semmle.label | Call to downloaddata |
+| test.ps1:117:1:117:13 | remoteStream | semmle.label | remoteStream |
+| test.ps1:117:17:117:59 | Call to new | semmle.label | Call to new |
+| test.ps1:117:47:117:58 | remoteBytes | semmle.label | remoteBytes |
+| test.ps1:118:41:118:53 | remoteStream | semmle.label | remoteStream |
 subpaths
diff --git a/powershell/ql/test/query-tests/security/cwe-502/test.ps1 b/powershell/ql/test/query-tests/security/cwe-502/test.ps1
index 7428591e2bcf..ce386bd07e9d 100644
--- a/powershell/ql/test/query-tests/security/cwe-502/test.ps1
+++ b/powershell/ql/test/query-tests/security/cwe-502/test.ps1
@@ -85,19 +85,34 @@ $input17 = Read-Host "Enter packed data" # $ Source
 $bytes17 = [Convert]::FromBase64String($input17)
 [MemoryPack.MemoryPackSerializer]::Deserialize($bytes17) # $ Alert
 
-# Test 18: self-serialized BinaryFormatter data should not be reported by the taint-based query
+# Test 18: Import-Clixml with untrusted path
+$input18 = Read-Host "Enter file path" # $ Source
+$obj18 = Import-Clixml -Path $input18 # $ Alert
+
+# Test 19: Import-Clixml with untrusted LiteralPath
+$input19 = Read-Host "Enter literal path" # $ Source
+$obj19 = Import-Clixml -LiteralPath $input19 # $ Alert
+
+# Test 20: ConvertFrom-CliXml with untrusted input (pipeline)
+$input20 = Read-Host "Enter CLIXML string" # $ Source
+$obj20 = $input20 | ConvertFrom-CliXml # $ Alert
+
+# Test 21: Import-Clixml with safe (hardcoded) path should not be flagged
+$safeObj = Import-Clixml -Path "C:\safe\config.xml"
+
+# Test 22: self-serialized BinaryFormatter data should not be reported by the taint-based query
 $safeFormatter = New-Object System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
 $safeStream = [System.IO.MemoryStream]::new()
 $safeFormatter.Serialize($safeStream, [PSCustomObject]@{ Name = "local" })
 $safeStream.Position = 0
 $safeObj = $safeFormatter.Deserialize($safeStream)
 
-# Test 19: file-controlled bytes deserialized with BinaryFormatter
+# Test 23: file-controlled bytes deserialized with BinaryFormatter
 $fileBytes = [System.IO.File]::ReadAllBytes("payload.bin") # $ Source
 $fileStream = [System.IO.MemoryStream]::new($fileBytes)
 $fileObj = $safeFormatter.Deserialize($fileStream) # $ Alert
 
-# Test 20: remote-controlled bytes deserialized with BinaryFormatter
+# Test 24: remote-controlled bytes deserialized with BinaryFormatter
 $remoteBytes = [System.Net.WebClient]::new().DownloadData("https://example.com/payload.bin") # $ Source
 $remoteStream = [System.IO.MemoryStream]::new($remoteBytes)
 $remoteObj = $safeFormatter.Deserialize($remoteStream) # $ Alert