Solution : https://service.sap.com/sap/support/notes/1414059 (SAP Service marketplace login required)
Key words : 
sapbwnews bw support package 26 netweaver '04 stack 26, bw back-end system, system stability reason, sap netweaver bw 7, delivered bw functions, sap nw bw 7, attached corrections remove, critical source code, attached corrections immediately, attached corrections apply
Related Notes : 
       
| 1270629 | SAPBINews NW7.0 BI ABAP Support Package 21 | 
| 1263691 | SAPBWNews NW BW 7.11 ABAP Support Package 03 | 
| 1260071 | SAPBINews NW 7.10 BI ABAP Support Package 08 | 
| 1227876 | SAPBINews NW7.01 BI ABAP Support Package 04 | 
| 888889 | Automatic checks for security notes using RSECNOTE |