diff --git a/src/H5Faccum.c b/src/H5Faccum.c
index 4d713576ca6..b45bce869bf 100644
--- a/src/H5Faccum.c
+++ b/src/H5Faccum.c
@@ -881,6 +881,11 @@ H5F__accum_free(H5F_shared_t *f_sh, H5FD_mem_t H5_ATTR_UNUSED type, haddr_t addr
                 H5_CHECKED_ASSIGN(overlap_size, size_t, (addr + size) - accum->loc, haddr_t);
                 new_accum_size = accum->size - overlap_size;
 
+                /* Ensure that the memmove operation won't overflow past the buffer's allocated size */
+                if (H5_IS_BUFFER_OVERFLOW(accum->buf + overlap_size, new_accum_size,
+                                          accum->buf + accum->alloc_size - 1)) {
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "memmove operation would overflow buffer");
+                }
                 /* Move the accumulator buffer information to eliminate the freed block */
                 memmove(accum->buf, accum->buf + overlap_size, new_accum_size);