Update CHANGELOG and library version for v3.15.1

Bug: 564595707
Change-Id: I3d5653194e9713ebbf305c6881593ef889d87cbb

CHANGELOG

diff --git a/CHANGELOG b/CHANGELOG
index fa08aac..10f30df 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,11 @@
+2026-09-21 v3.15.1
+  This release is ABI compatible with the last release. See
+  https://aomedia.googlesource.com/aom/+log/v3.15.0..v3.15.1 for all the
+  commits in this release.
+
+  - Bug Fixes
+    * b:558679217: Tune VMAF mode regression
+
 2026-08-25 v3.15.0
   This release is ABI compatible with the last release.
 

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2170c4f..1877de7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,7 +23,7 @@
 
 # VERSION is the release version of the library. It should be updated at the
 # same time as the LT_* variables.
-project(AOM LANGUAGES C CXX VERSION 3.15.0)
+project(AOM LANGUAGES C CXX VERSION 3.15.1)
 
 # GENERATED source property global visibility.
 if(POLICY CMP0118)
@@ -59,7 +59,7 @@
 #
 # The VERSION number in project() should be updated when these variables are.
 set(LT_CURRENT 18)
-set(LT_REVISION 0)
+set(LT_REVISION 1)
 set(LT_AGE 15)
 math(EXPR SO_VERSION "${LT_CURRENT} - ${LT_AGE}")
 set(SO_FILE_VERSION "${SO_VERSION}.${LT_AGE}.${LT_REVISION}")