diff --git a/script/tf-coverity/common-def.sh b/script/tf-coverity/common-def.sh
index a7ec236..f2241ec 100644
--- a/script/tf-coverity/common-def.sh
+++ b/script/tf-coverity/common-def.sh
@@ -71,7 +71,7 @@
 
 # mbed TLS source tag to checkout when building Trusted Firmware with Trusted
 # Board Boot support.
-MBED_TLS_SOURCES_TAG="mbedtls-2.25.0"
+MBED_TLS_SOURCES_TAG="mbedtls-2.26.0"
 
 ARMCLANG_PATH="$(set_armclang_toolchain)"