diff --git a/glibc.spec b/glibc.spec
index c161287..8c7d3b0 100644
--- a/glibc.spec
+++ b/glibc.spec
@@ -1,4 +1,4 @@
-%global glibcsrcdir glibc-2.39.9000-355-gdd144dce21
+%global glibcsrcdir glibc-2.39.9000-373-g21738846a1
 %global glibcversion 2.39.9000
 # Pre-release tarballs are pulled in from git using a command that is
 # effectively:
@@ -170,7 +170,7 @@ Version: %{glibcversion}
 # - It allows using the Release number without the %%dist tag in the dependency
 #   generator to make the generated requires interchangeable between Rawhide
 #   and ELN (.elnYY < .fcXX).
-%global baserelease 27
+%global baserelease 28
 Release: %{baserelease}%{?dist}
 
 # Licenses:
@@ -2561,6 +2561,28 @@ update_gconv_modules_cache ()
 %endif
 
 %changelog
+* Thu Jun 27 2024 Patsy Griffin <patsy@redhat.com> - 2.39.9000-28
+- Auto-sync with upstream branch master,
+  commit 21738846a19eb4a36981efd37d9ee7cb6d687494.
+- time: Avoid memcmp overread in tzset (bug 31931)
+- Fix strnlen doc re array size
+- arm: Avoid UB in elf_machine_rel()
+- LoongArch: Fix tst-gnu2-tls2 test case
+- posix: Fix pidfd_spawn/pidfd_spawnp leak if execve fails (BZ 31695)
+- INSTALL: regenerate
+- Revert "MIPSr6/math: Use builtin fma and fmaf"
+- INSTALL: Fix typo ibmlondouble to ibmlongdouble
+- RISC-V: Execute a PAUSE hint in spin loops
+- MIPSr6/math: Use builtin fma and fmaf
+- po: incorporate translations (cs, de, hr, ko, pl, ro, ru, sv, uk, zh_CN)
+- mtrace: make shell commands robust against meta characters
+- hppa/vdso: Add wrappers for vDSO functions
+- Update hppa libm-test-ulps
+- Benchtests: Remove broken walk benchmarks
+- Update hppa libm-test-ulps
+- RISC-V: Update ulps
+- MIPS: Update ulps
+
 * Thu Jun 20 2024 Florian Weimer <fweimer@redhat.com> - 2.39.9000-27
 - Auto-sync with upstream branch master,
   commit dd144dce21c864781fade4561581d50fb4549956:
diff --git a/sources b/sources
index e2c9590..9ef70a0 100644
--- a/sources
+++ b/sources
@@ -1 +1 @@
-SHA512 (glibc-2.39.9000-355-gdd144dce21.tar.xz) = 056ca43b7baafa4fff1015fb77371590a3bcaf636a98697f8607741423b11743b7d3462a7a60d0c4c856c10fb7cd723ba1d80abfe0c27a4477b5ee9156b470a3
+SHA512 (glibc-2.39.9000-373-g21738846a1.tar.xz) = 4f7f6866d3341951e015d76ab33b79d3c0bb00fc6e63c01f5acd6372179de9d088e894a62158c69658694c37b7fe98cd77f6c03754acee7803e48020c278b218