CVE-2026-89608 ecryptfs: pass packet set buffer size to parser
A buffer size miscalculation in the ecryptfs kernel module can lead to memory corruption, potentially allowing attackers to cause denial of service or execute arbitrary code.
- 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-2026-89608?
CVE-2026-89608 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: pass packet set buffer size to parser
ecryptfs_parse_packet_set() receives a pointer into the file header, but it calculates the remaining packet buffer size from PAGE_SIZE - 8. For version 1 headers the packet set starts later in the header, so this can overstate the available buffer.
Pass the actual packet set buffer length from the caller and calculate per-packet limits from the remaining bytes in that buffer. Recompute the remaining length after consuming a tag 3 packet before parsing the following tag 11 packet.
Which versions are affected by CVE-2026-89608?
How do I fix CVE-2026-89608?
Apply the vendor's patch.
Is CVE-2026-89608 being exploited?
There is no known exploitation of CVE-2026-89608 in the wild and no public exploit code.
Sources
Also known as AZL-100184, BELL-CVE-2026-89608, DEBIAN-CVE-2026-89608, GHSA-m87w-w8mv-rf6c, UBUNTU-CVE-2026-89608.