CVE-2026-43494 net/rds: reset op_nents when zerocopy page pin fails
A use-after-free vulnerability in the Linux kernel RDS module allows attackers to execute arbitrary code or escalate privileges via crafted network messages.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-43494?
CVE-2026-43494 is a high-severity use after free vulnerability in Linux kernel, published on 21 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net/rds: reset op_nents when zerocopy page pin fails
When iov_iter_get_pages2() fails in rds_message_zcopy_from_user(), the pinned pages are released with put_page(), and rm->data.op_mmp_znotifier is cleared. But we fail to properly clear rm->data.op_nents.
Later when rds_message_purge() is called from rds_sendmsg() the cleanup loop iterates over the incorrectly non zero number of op_nents and frees them again.
Fix this by properly resetting op_nents when it should be in rds_message_zcopy_from_user().
Which versions are affected by CVE-2026-43494?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43494?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-43494 being exploited?
There is no known exploitation of CVE-2026-43494 in the wild and no public exploit code.
Public exploit code: 7 proofs of concept on GitHub.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-87083, BELL-CVE-2026-43494, DEBIAN-CVE-2026-43494, GHSA-m5w6-2mrp-4227, ROOT-OS-DEBIAN-11-CVE-2026-43494, ROOT-OS-DEBIAN-12-CVE-2026-43494 and 2 more.