UBUNTU-CVE-2026-31694
Vulnerability Summary
Timeline
Description
In the Linux kernel, the following vulnerability has been resolved: fuse: reject oversized dirents in page cache fuse_add_dirent_to_cache() computes a serialized dirent size from the server-controlled namelen field and copies the dirent into a single page-cache page. The existing logic only checks whether the dirent fits in the remaining space of the current page and advances to a fresh page if not. It never checks whether the dirent itself exceeds PAGE_SIZE. As a result, a malicious FUSE server can return a dirent with namelen=4095, producing a serialized record size of 4120 bytes. On 4 KiB page systems this causes memcpy() to overflow the cache page by 24 bytes into the following kernel page. Reject dirents that cannot fit in a single page before copying them into the readdir cache.
CVSS Metrics
- v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected Systems
- ubuntu•linux
all | all | all | all | all
- ubuntu•linux-allwinner-5.19
all
- ubuntu•linux-aws
all | all | all | all | all
- ubuntu•linux-aws-5.0
all
- ubuntu•linux-aws-5.11
all
- ubuntu•linux-aws-5.13
all
- ubuntu•linux-aws-5.15
all
- ubuntu•linux-aws-5.19
all
- ubuntu•linux-aws-5.3
all
- ubuntu•linux-aws-5.4
all
- ubuntu•linux-aws-5.8
all
- ubuntu•linux-aws-6.14
all
- ubuntu•linux-aws-6.17
all
- ubuntu•linux-aws-6.2
all
- ubuntu•linux-aws-6.5
all
- ubuntu•linux-aws-6.8
all
- ubuntu•linux-aws-fips
all
- ubuntu•linux-aws-hwe
all
- ubuntu•linux-azure
all | all | all | all | all | all
- ubuntu•linux-azure-4.15
all
- ubuntu•linux-azure-5.11
all
- ubuntu•linux-azure-5.13
all
- ubuntu•linux-azure-5.15
all
- ubuntu•linux-azure-5.19
all
- ubuntu•linux-azure-5.3
all
- ubuntu•linux-azure-5.4
all
- ubuntu•linux-azure-5.8
all
- ubuntu•linux-azure-6.11
all
- ubuntu•linux-azure-6.14
all
- ubuntu•linux-azure-6.17
all
- ubuntu•linux-azure-6.2
all
- ubuntu•linux-azure-6.5
all
- ubuntu•linux-azure-6.8
all
- ubuntu•linux-azure-edge
all
- ubuntu•linux-azure-fde
all | all | all | all | all
- ubuntu•linux-azure-fde-5.15
all
- ubuntu•linux-azure-fde-5.19
all
- ubuntu•linux-azure-fde-6.14
all
- ubuntu•linux-azure-fde-6.17
all
- ubuntu•linux-azure-fde-6.2
all
- ubuntu•linux-azure-fde-6.8
all
- ubuntu•linux-azure-fips
all
- ubuntu•linux-azure-nvidia
all
- ubuntu•linux-azure-nvidia-6.14
all
- ubuntu•linux-bluefield
all | all
- ubuntu•linux-fips
all
- ubuntu•linux-gcp
all | all | all | all | all | all
- ubuntu•linux-gcp-4.15
all
- ubuntu•linux-gcp-5.11
all
- ubuntu•linux-gcp-5.13
all
Showing first 50 affected entries in server-rendered view.