CVE-2026-89606 ecryptfs: reject too-small tag 70 packets
A malformed packet in the Linux kernel ecryptfs module can cause an integer underflow, potentially leading to a denial of service.
- 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-2026-89606?
CVE-2026-89606 is a high-severity vulnerability in Linux, published on 11 Sep 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:
ecryptfs: reject too-small tag 70 packets
ecryptfs_parse_tag_70_packet() subtracts fixed metadata fields from the parsed packet body size to derive the encrypted filename size. A malformed packet with a body smaller than those fixed fields can underflow that size calculation.
Reject tag 70 packets before the subtraction unless the body contains the signature, cipher code, and at least one byte of encrypted filename data.
Which versions are affected by CVE-2026-89606?
How do I fix CVE-2026-89606?
Apply the vendor's patch.
Is CVE-2026-89606 being exploited?
There is no known exploitation of CVE-2026-89606 in the wild and no public exploit code.
Sources
Also known as AZL-100812, BELL-CVE-2026-89606, DEBIAN-CVE-2026-89606, GHSA-x8vp-v84j-h4hg, UBUNTU-CVE-2026-89606.