Integer overflow (wraparound) vulnerability in Corosync’s join message sanity validation in exec/totemsrp.c. The flaw is in check_memb_join_sanity(), where proc_list_entries and failed_list_entries are attacker-controlled 32-bit unsigned values received from the network and are added together before being promoted to size_t. This allows the addition (proc_list_entries + failed_list_entries) to wrap around in 32-bit arithmetic (e.g., 0x80000000 + 0x80000000 = 0), causing required_len to be calculated too small and allowing a short packet to pass validation. As a result, Corosync proceeds with processing malformed input that should have been rejected, which can be exploited remotely without authentication in totemudp/totemudpu mode via crafted UDP packets to crash the service, resulting in a denial of service.
This issue has been addressed in the following products: Red Hat Enterprise Linux 10 Via RHSA-2026:13644 https://access.redhat.com/errata/RHSA-2026:13644
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2026:13657 https://access.redhat.com/errata/RHSA-2026:13657
This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2026:13673 https://access.redhat.com/errata/RHSA-2026:13673
This issue has been addressed in the following products: Red Hat Enterprise Linux 10.0 Extended Update Support Via RHSA-2026:14205 https://access.redhat.com/errata/RHSA-2026:14205
This issue has been addressed in the following products: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions Via RHSA-2026:14211 https://access.redhat.com/errata/RHSA-2026:14211
This issue has been addressed in the following products: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On Via RHSA-2026:14215 https://access.redhat.com/errata/RHSA-2026:14215
This issue has been addressed in the following products: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Via RHSA-2026:14210 https://access.redhat.com/errata/RHSA-2026:14210
This issue has been addressed in the following products: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions Red Hat Enterprise Linux 8.6 Telecommunications Update Service Via RHSA-2026:14214 https://access.redhat.com/errata/RHSA-2026:14214
This issue has been addressed in the following products: Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions Red Hat Enterprise Linux 8.8 Telecommunications Update Service Via RHSA-2026:14216 https://access.redhat.com/errata/RHSA-2026:14216
This issue has been addressed in the following products: Red Hat Enterprise Linux 9.4 Extended Update Support Via RHSA-2026:14212 https://access.redhat.com/errata/RHSA-2026:14212
This issue has been addressed in the following products: Red Hat Enterprise Linux 9.6 Extended Update Support Via RHSA-2026:14213 https://access.redhat.com/errata/RHSA-2026:14213
This issue has been addressed in the following products: Red Hat Enterprise Linux 10 Via RHSA-2026:19043 https://access.redhat.com/errata/RHSA-2026:19043
This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2026:19200 https://access.redhat.com/errata/RHSA-2026:19200