Division by zero in Linux kernel - CVE-2026-98299
Published: October 7, 2026
Vulnerability identifier: #VU153726
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-98299
CWE-ID: CWE-369
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to division by zero in the Linux kernel functions tcp_rcvbuf_grow() and tcp_rcv_space_adjust() when processing incoming TCP data with a zero receive-queue space value. A remote attacker can send TCP data that triggers a kernel crash to cause a denial of service.
Exploitation requires tcp_rmem[1] to be configured to a very small value, such as 1.
Affected software
Linux kernel
How to mitigate CVE-2026-98299
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/1c4bb940c3bb4325bb88ac1b7eaf5faaa39e7d63
- https://git.kernel.org/stable/c/60df201dbb19a1bf6478b56d100f7ae1fe90e46a
- https://git.kernel.org/stable/c/67b83c15bed9eeeb8d1a6dbf88a5f79525970173
- https://git.kernel.org/stable/c/7898bda1ebc198f5559b301a96dd5398edd4d4d3
- https://git.kernel.org/stable/c/83a945a529d6e002dd7339c532288a931f463dba
- https://git.kernel.org/stable/c/879907631b9e70eedb62d76461b29afa106ebe7a
- https://git.kernel.org/stable/c/8e32532d0fa3191ecf9524b0e6bafa0832e712ba
- https://git.kernel.org/stable/c/9a4f49bf8d2da4e52e904f60c29cca317bab9b3a