diff --git a/blockchain/all_challenges/2019/de1ctf/EasyEOS/backend/yarn.lock b/blockchain/all_challenges/2019/de1ctf/EasyEOS/backend/yarn.lock
index ed0bc0e..d473fcf 100644
--- a/blockchain/all_challenges/2019/de1ctf/EasyEOS/backend/yarn.lock
+++ b/blockchain/all_challenges/2019/de1ctf/EasyEOS/backend/yarn.lock
@@ -492,9 +492,9 @@ safe-buffer@^5.0.1, safe-buffer@^5.1.0, safe-buffer@^5.1.1, safe-buffer@^5.1.2:
   integrity sha512-fZEwUGbVl7kouZs1jCdMLdt95hdIv0ZeHg6L7qPeciMZhZ+/gdesW4wgTARkrFWEpspjEATAzUGPG8N2jJiwbg==
 
 "semver@2 || 3 || 4 || 5", semver@^5.5.0:
-  version "5.7.0"
-  resolved "https://registry.yarnpkg.com/semver/-/semver-5.7.0.tgz#790a7cf6fea5459bac96110b29b60412dc8ff96b"
-  integrity sha512-Ya52jSX2u7QKghxeoFGpLwCtGlt7j0oY9DYb5apt9nPlJ42ID+ulTXESnt/qAQcoSERyZ5sl3LDIOw0nAn/5DA==
+  version "5.7.2"
+  resolved "https://registry.yarnpkg.com/semver/-/semver-5.7.2.tgz#48d55db737c3287cd4835e17fa13feace1c41ef8"
+  integrity sha512-cBznnQ9KjJqU67B52RMC65CMarK2600WFnbkcaiwWq3xy/5haFJlshgnpjovMVJ+Hff49d8GEn0b87C5pDQ10g==
 
 sha.js@^2.4.0, sha.js@^2.4.8:
   version "2.4.11"