diff --git a/extra/modules/pb-response-correction/src/main/java/org/prebid/server/hooks/modules/pb/response/correction/core/correction/appvideohtml/AppVideoHtmlCorrection.java b/extra/modules/pb-response-correction/src/main/java/org/prebid/server/hooks/modules/pb/response/correction/core/correction/appvideohtml/AppVideoHtmlCorrection.java
index 3df769e52cb..5b3ee918e86 100644
--- a/extra/modules/pb-response-correction/src/main/java/org/prebid/server/hooks/modules/pb/response/correction/core/correction/appvideohtml/AppVideoHtmlCorrection.java
+++ b/extra/modules/pb-response-correction/src/main/java/org/prebid/server/hooks/modules/pb/response/correction/core/correction/appvideohtml/AppVideoHtmlCorrection.java
@@ -21,6 +21,7 @@
 
 import java.util.Collection;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.regex.Pattern;
 
@@ -29,7 +30,7 @@ public class AppVideoHtmlCorrection implements Correction {
     private static final ConditionalLogger conditionalLogger = new ConditionalLogger(
             LoggerFactory.getLogger(AppVideoHtmlCorrection.class));
 
-    private static final Pattern VAST_XML_PATTERN = Pattern.compile("<\\w*VAST\\w+", Pattern.CASE_INSENSITIVE);
+    private static final Pattern VAST_XML_PATTERN = Pattern.compile(".*<\\s*VAST\\s+.*", Pattern.CASE_INSENSITIVE);
     private static final TypeReference<ExtPrebid<ExtBidPrebid, ObjectNode>> EXT_BID_PREBID_TYPE_REFERENCE =
             new TypeReference<>() {
             };
@@ -42,7 +43,7 @@ public class AppVideoHtmlCorrection implements Correction {
     private final double logSamplingRate;
 
     public AppVideoHtmlCorrection(ObjectMapper mapper, double logSamplingRate) {
-        this.mapper = mapper;
+        this.mapper = Objects.requireNonNull(mapper);
         this.logSamplingRate = logSamplingRate;
     }
 
diff --git a/extra/modules/pb-response-correction/src/test/java/org/prebid/server/hooks/modules/pb/response/correction/core/correction/appvideohtml/AppVideoHtmlCorrectionTest.java b/extra/modules/pb-response-correction/src/test/java/org/prebid/server/hooks/modules/pb/response/correction/core/correction/appvideohtml/AppVideoHtmlCorrectionTest.java
index 537e79943cd..9b36b0210da 100644
--- a/extra/modules/pb-response-correction/src/test/java/org/prebid/server/hooks/modules/pb/response/correction/core/correction/appvideohtml/AppVideoHtmlCorrectionTest.java
+++ b/extra/modules/pb-response-correction/src/test/java/org/prebid/server/hooks/modules/pb/response/correction/core/correction/appvideohtml/AppVideoHtmlCorrectionTest.java
@@ -77,7 +77,7 @@ public void applyShouldNotChangeBidResponsesWhenBidIsVideoAndHasVastXmlInAdm() {
         final List<BidderResponse> givenResponses = List.of(
                 BidderResponse.of("bidderA", null, 100),
                 BidderResponse.of("bidderB", BidderSeatBid.of(
-                        List.of(givenBid("<anythingvAstanything", BidType.video))), 100));
+                        List.of(givenBid("< \tVAST anything>", BidType.video))), 100));
 
         // when
         final List<BidderResponse> actual = target.apply(givenConfig, givenResponses);
diff --git a/src/test/groovy/org/prebid/server/functional/tests/module/responsecorrenction/ResponseCorrectionSpec.groovy b/src/test/groovy/org/prebid/server/functional/tests/module/responsecorrenction/ResponseCorrectionSpec.groovy
index 589925b3e34..c848c30e2e4 100644
--- a/src/test/groovy/org/prebid/server/functional/tests/module/responsecorrenction/ResponseCorrectionSpec.groovy
+++ b/src/test/groovy/org/prebid/server/functional/tests/module/responsecorrenction/ResponseCorrectionSpec.groovy
@@ -37,6 +37,8 @@ class ResponseCorrectionSpec extends ModuleBaseSpec {
              "adapters.generic.modifying-vast-xml-allowed": "false"] +
                     responseCorrectionConfig)
 
+    private final static int OPTIMAL_MAX_LENGTH = 20
+
     def "PBS shouldn't modify response when in account correction module disabled"() {
         given: "Start up time"
         def start = Instant.now()
@@ -326,7 +328,7 @@ class ResponseCorrectionSpec extends ModuleBaseSpec {
 
         and: "Set bidder response"
         def bidResponse = BidResponse.getDefaultBidResponse(bidRequest).tap {
-            seatbid[0].bid[0].setAdm(PBSUtils.getRandomCase("<${PBSUtils.randomString}VAST${PBSUtils.randomString}"))
+            seatbid[0].bid[0].setAdm(PBSUtils.getRandomCase(admValue))
         }
         bidder.setResponse(bidRequest.id, bidResponse)
 
@@ -352,6 +354,69 @@ class ResponseCorrectionSpec extends ModuleBaseSpec {
 
         and: "Response shouldn't contain warnings"
         assert !response.ext.warnings
+
+        where:
+        admValue << [
+                "${PBSUtils.randomString}<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST ${PBSUtils.randomString}",
+                "${PBSUtils.randomString}<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST ${PBSUtils.randomString}>",
+                "${PBSUtils.randomString}${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST ${PBSUtils.randomString}>",
+                "<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST${' ' * PBSUtils.getRandomNumber(1, OPTIMAL_MAX_LENGTH)}",
+                "<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST${' ' * PBSUtils.getRandomNumber(1, OPTIMAL_MAX_LENGTH)}>",
+                "<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST${' ' * PBSUtils.getRandomNumber(1, OPTIMAL_MAX_LENGTH)}${PBSUtils.randomString}>"
+        ]
+    }
+
+    def "PBS should modify response when requested video impression respond with invalid adm VAST keyword"() {
+        given: "Start up time"
+        def start = Instant.now()
+
+        and: "Default bid request with APP and Video imp"
+        def bidRequest = getDefaultVideoRequest(APP)
+
+        and: "Set bidder response"
+        def bidResponse = BidResponse.getDefaultBidResponse(bidRequest).tap {
+            seatbid[0].bid[0].setAdm(PBSUtils.getRandomCase(admValue))
+        }
+        bidder.setResponse(bidRequest.id, bidResponse)
+
+        and: "Save account with enabled response correction module"
+        def accountWithResponseCorrectionModule = accountConfigWithResponseCorrectionModule(bidRequest)
+        accountDao.save(accountWithResponseCorrectionModule)
+
+        when: "PBS processes auction request"
+        def response = pbsServiceWithResponseCorrectionModule.sendAuctionRequest(bidRequest)
+
+        then: "PBS should emit log"
+        def logsByTime = pbsServiceWithResponseCorrectionModule.getLogsByTime(start)
+        def bidId = bidResponse.seatbid[0].bid[0].id
+        def responseCorrection = getLogsByText(logsByTime, bidId)
+        assert responseCorrection.size() == 1
+        assert responseCorrection.any {
+            it.contains("Bid $bidId of bidder generic: changing media type to banner" as String)
+        }
+
+        and: "Response should contain seatBid"
+        assert response.seatbid.size() == 1
+
+        and: "Response should contain single seatBid with proper media type"
+        assert response.seatbid.bid.ext.prebid.type.flatten() == [BANNER]
+
+        and: "Response should contain single seatBid with proper meta media type"
+        assert response.seatbid.bid.ext.prebid.meta.mediaType.flatten() == [VIDEO.value]
+
+        and: "Response shouldn't contain errors"
+        assert !response.ext.errors
+
+        and: "Response shouldn't contain warnings"
+        assert !response.ext.warnings
+
+        where:
+        admValue << [
+                "<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST${PBSUtils.randomString}",
+                "<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST",
+                "<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST>",
+                "<${PBSUtils.randomString}VAST${' ' * PBSUtils.getRandomNumber(1, OPTIMAL_MAX_LENGTH)}"
+        ]
     }
 
     def "PBS should modify response when requested #mediaType impression respond with adm VAST keyword"() {
@@ -365,7 +430,7 @@ class ResponseCorrectionSpec extends ModuleBaseSpec {
 
         and: "Set bidder response"
         def bidResponse = BidResponse.getDefaultBidResponse(bidRequest).tap {
-            seatbid[0].bid[0].setAdm(PBSUtils.getRandomCase("<${PBSUtils.randomString}VAST${PBSUtils.randomString}"))
+            seatbid[0].bid[0].setAdm(PBSUtils.getRandomCase(admValue))
         }
         bidder.setResponse(bidRequest.id, bidResponse)
 
@@ -376,7 +441,7 @@ class ResponseCorrectionSpec extends ModuleBaseSpec {
         when: "PBS processes auction request"
         def response = pbsServiceWithResponseCorrectionModule.sendAuctionRequest(bidRequest)
 
-        then: "PBS shouldn't emit log"
+        then: "PBS should emit log"
         def logsByTime = pbsServiceWithResponseCorrectionModule.getLogsByTime(start)
         def bidId = bidResponse.seatbid[0].bid[0].id
         def responseCorrection = getLogsByText(logsByTime, bidId)
@@ -401,7 +466,16 @@ class ResponseCorrectionSpec extends ModuleBaseSpec {
         assert !response.ext.warnings
 
         where:
-        mediaType << [BANNER, AUDIO, NATIVE]
+        mediaType | admValue
+        BANNER    | "${PBSUtils.randomString}<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST${PBSUtils.randomString}"
+        BANNER    | "<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST${' ' * PBSUtils.getRandomNumber(1, OPTIMAL_MAX_LENGTH)}"
+        BANNER    | "<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}}VAST${' ' * PBSUtils.getRandomNumber(1, OPTIMAL_MAX_LENGTH)}${PBSUtils.randomString}"
+        AUDIO     | "${PBSUtils.randomString}<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST${PBSUtils.randomString}"
+        AUDIO     | "<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST${' ' * PBSUtils.getRandomNumber(1, OPTIMAL_MAX_LENGTH)}"
+        AUDIO     | "<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}}VAST${' ' * PBSUtils.getRandomNumber(1, OPTIMAL_MAX_LENGTH)}${PBSUtils.randomString}"
+        NATIVE    | "${PBSUtils.randomString}<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST${PBSUtils.randomString}"
+        NATIVE    | "<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}VAST${' ' * PBSUtils.getRandomNumber(1, OPTIMAL_MAX_LENGTH)}"
+        NATIVE    | "<${' ' * PBSUtils.getRandomNumber(0, OPTIMAL_MAX_LENGTH)}}VAST${' ' * PBSUtils.getRandomNumber(1, OPTIMAL_MAX_LENGTH)}${PBSUtils.randomString}"
     }
 
     def "PBS shouldn't modify response meta.mediaType to video and emit logs when requested impression with video and adm obj with asset"() {