CVE-2026-98323 RDMA/siw: Bound fragmented header copies by the remaining length
A buffer overflow in the Linux kernel RDMA driver allows attackers to overwrite memory and potentially execute code or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98323?
CVE-2026-98323 is a critical memory corruption vulnerability in Linux, published on 6 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
RDMA/siw: Bound fragmented header copies by the remaining length
siw_get_hdr() can receive an extended DDP/RDMAP header across more than one TCP callback. The first callback may receive most of the header, while the next one still limits the copy to hdrlen - MIN_DDP_HDR instead of the number of missing bytes. This makes the destination move past the end of the header and overwrite the receive state, including fpdu_part_rcvd. A later callback can then use a negative fpdu_part_rcvd value as a copy offset, which creates an OOB write.
Use the number of header bytes already received when calculating the next copy length.
Which versions are affected by CVE-2026-98323?
How do I fix CVE-2026-98323?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-98323 being exploited?
There is no known exploitation of CVE-2026-98323 in the wild and no public exploit code.
Sources
Also known as AZL-106458, BELL-CVE-2026-98323, DEBIAN-CVE-2026-98323, GHSA-6mmc-6x3m-rgjh, UBUNTU-CVE-2026-98323.