diff --git a/pom.xml b/pom.xml
index 7f81cde0..b6e28389 100644
--- a/pom.xml
+++ b/pom.xml
@@ -7,7 +7,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.6.4</version>
+        <version>2.6.5</version>
         <relativePath/>
     </parent>
 
@@ -57,7 +57,8 @@
         <spring.cloud.version>2021.0.1</spring.cloud.version>
         <h2.version>2.1.210</h2.version>
         <hibernate.version>5.6.5.Final</hibernate.version>
-        <dgc.lib.version>1.3.0</dgc.lib.version>
+        <dgc.lib.version>1.3.1</dgc.lib.version>
+        <jackson.databind.version>2.13.2.1</jackson.databind.version>
         <!-- plugins -->
         <plugin.maven-assembly.version>3.3.0</plugin.maven-assembly.version>
         <plugin.checkstyle.version>3.1.2</plugin.checkstyle.version>
@@ -266,6 +267,12 @@
             <artifactId>shedlock-spring</artifactId>
             <version>${shedlock.version}</version>
         </dependency>
+        <!-- Explicitly needed due to https://nvd.nist.gov/vuln/detail/CVE-2020-36518 until core is updated -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson.databind.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
diff --git a/src/main/java/eu/europa/ec/dgc/gateway/repository/SignerInformationRepository.java b/src/main/java/eu/europa/ec/dgc/gateway/repository/SignerInformationRepository.java
index 121992cf..5dc1dbae 100644
--- a/src/main/java/eu/europa/ec/dgc/gateway/repository/SignerInformationRepository.java
+++ b/src/main/java/eu/europa/ec/dgc/gateway/repository/SignerInformationRepository.java
@@ -52,16 +52,16 @@ public interface SignerInformationRepository extends JpaRepository<SignerInforma
     @Query("DELETE FROM SignerInformationEntity s WHERE s.deletedAt < :threshold")
     int deleteDeletedSignerInformationOlderThan(@Param("threshold") ZonedDateTime threshold);
 
-    List<SignerInformationEntity> getByCertificateType(SignerInformationEntity.CertificateType type,
+    List<SignerInformationEntity> getByCertificateTypeAndDeletedAtIsNull(SignerInformationEntity.CertificateType type,
                                                        Pageable pageable);
 
-    List<SignerInformationEntity> getByCertificateType(SignerInformationEntity.CertificateType type);
+    List<SignerInformationEntity> getByCertificateTypeAndDeletedAtIsNull(SignerInformationEntity.CertificateType type);
 
-    List<SignerInformationEntity> getByCertificateTypeAndCountry(
+    List<SignerInformationEntity> getByCertificateTypeAndCountryAndDeletedAtIsNull(
         SignerInformationEntity.CertificateType type, String countryCode,
         Pageable pageable);
 
-    List<SignerInformationEntity> getByCertificateTypeAndCountry(
+    List<SignerInformationEntity> getByCertificateTypeAndCountryAndDeletedAtIsNull(
         SignerInformationEntity.CertificateType type, String countryCode);
 
     @Query(SELECT_SINCE)
diff --git a/src/main/java/eu/europa/ec/dgc/gateway/service/SignerInformationService.java b/src/main/java/eu/europa/ec/dgc/gateway/service/SignerInformationService.java
index 04e6c7c9..d5aa9945 100644
--- a/src/main/java/eu/europa/ec/dgc/gateway/service/SignerInformationService.java
+++ b/src/main/java/eu/europa/ec/dgc/gateway/service/SignerInformationService.java
@@ -79,7 +79,7 @@ public List<SignerInformationEntity> getSignerInformation() {
      * @return List of SignerInformation
      */
     public List<SignerInformationEntity> getSignerInformation(SignerInformationEntity.CertificateType type) {
-        return signerInformationRepository.getByCertificateType(type);
+        return signerInformationRepository.getByCertificateTypeAndDeletedAtIsNull(type);
     }
 
     /**
@@ -92,7 +92,7 @@ public List<SignerInformationEntity> getSignerInformation(SignerInformationEntit
     public List<SignerInformationEntity> getSignerInformation(
         String countryCode,
         SignerInformationEntity.CertificateType type) {
-        return signerInformationRepository.getByCertificateTypeAndCountry(type, countryCode);
+        return signerInformationRepository.getByCertificateTypeAndCountryAndDeletedAtIsNull(type, countryCode);
     }
 
     /**
@@ -136,10 +136,10 @@ public List<SignerInformationEntity> getSignerInformation(SignerInformationEntit
         } else if (ifModifiedSince != null) {
             return signerInformationRepository.getByCertificateTypeIsSince(type, ifModifiedSince);
         } else if (page != null && size != null) {
-            return signerInformationRepository.getByCertificateType(type,
+            return signerInformationRepository.getByCertificateTypeAndDeletedAtIsNull(type,
                 PageRequest.of(page, size));
         } else {
-            return signerInformationRepository.getByCertificateType(type);
+            return signerInformationRepository.getByCertificateTypeAndDeletedAtIsNull(type);
         }
     }
 
@@ -166,10 +166,10 @@ public List<SignerInformationEntity> getSignerInformation(
             return signerInformationRepository.getByCertificateTypeAndCountryIsSince(type, countryCode,
                 ifModifiedSince);
         } else if (page != null && size != null) {
-            return signerInformationRepository.getByCertificateTypeAndCountry(type, countryCode,
+            return signerInformationRepository.getByCertificateTypeAndCountryAndDeletedAtIsNull(type, countryCode,
                 PageRequest.of(page, size));
         } else {
-            return signerInformationRepository.getByCertificateTypeAndCountry(type, countryCode);
+            return signerInformationRepository.getByCertificateTypeAndCountryAndDeletedAtIsNull(type, countryCode);
         }
     }
 
@@ -308,7 +308,7 @@ public void deleteSignerCertificate(
      */
     public List<CmsPackageDto> getCmsPackage(String country) {
         return signerInformationRepository
-            .getByCertificateTypeAndCountry(SignerInformationEntity.CertificateType.DSC, country)
+            .getByCertificateTypeAndCountryAndDeletedAtIsNull(SignerInformationEntity.CertificateType.DSC, country)
             .stream()
             .map(this::addCertificateToSignaturePayload)
             .map(it -> new CmsPackageDto(it.getSignature(), it.getId(), CmsPackageDto.CmsPackageTypeDto.DSC))
diff --git a/src/test/java/eu/europa/ec/dgc/gateway/service/SignerInformationServiceTest.java b/src/test/java/eu/europa/ec/dgc/gateway/service/SignerInformationServiceTest.java
index 0b8dd37c..fd13bf52 100644
--- a/src/test/java/eu/europa/ec/dgc/gateway/service/SignerInformationServiceTest.java
+++ b/src/test/java/eu/europa/ec/dgc/gateway/service/SignerInformationServiceTest.java
@@ -154,7 +154,7 @@ void testSuccessfulGetSignerInformationByTypeAndCountryIsSincePageable() throws
         List<SignerInformationEntity> signerInformationEntities =
             signerInformationService.getSignerInformation(SignerInformationEntity.CertificateType.DSC,
                 null, null, null);
-        Assertions.assertEquals(7, signerInformationEntities.size());
+        Assertions.assertEquals(6, signerInformationEntities.size());
 
         List<SignerInformationEntity> signerInformationEntities2 = signerInformationService.getSignerInformation(
             SignerInformationEntity.CertificateType.DSC,
@@ -244,9 +244,16 @@ void testSuccessfulAddingNewSignerInformationAndDelete() throws Exception {
             countryCode
         );
 
-        List<SignerInformationEntity> entities =
-            signerInformationRepository.getByCertificateType(SignerInformationEntity.CertificateType.DSC);
+        // Deleted certificate should not be returned in queries without isSince
+        List<SignerInformationEntity> entitiesByCertificateType =
+            signerInformationRepository.getByCertificateTypeAndDeletedAtIsNull(SignerInformationEntity.CertificateType.DSC);
+        Assertions.assertTrue(entitiesByCertificateType.isEmpty());
+        List<SignerInformationEntity> entitiesByCertificateTypeAndCountry =
+                signerInformationRepository.getByCertificateTypeAndCountryAndDeletedAtIsNull(
+                        SignerInformationEntity.CertificateType.DSC, countryCode);
+        Assertions.assertTrue(entitiesByCertificateTypeAndCountry.isEmpty());
 
+        List<SignerInformationEntity> entities = signerInformationRepository.findAll();
         Assertions.assertFalse(entities.isEmpty());
         SignerInformationEntity deletedSignerInformationEntity = entities.get(0);
         Assertions.assertEquals(createdSignerInformationEntity.get().getThumbprint(), deletedSignerInformationEntity.getThumbprint());