# CVE-2026-89652

## Summary

- **CVE ID:** CVE-2026-89652
- **Severity:** CRITICAL
- **CVSS Score:** 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
- **CWE:** N/A
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 14, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:

ceph: bound copied dentry name length in NFS export get_name

ceph_get_name() copies the MDS-supplied name into the caller's
NAME_MAX-sized buffer with memcpy(name, rinfo->dname, rinfo->dname_len)
and then writes name[rinfo->dname_len] = 0, without checking dname_len
against NAME_MAX. A malicious or buggy MDS that returns a LOOKUPNAME reply
with dname_len > NAME_MAX overflows the buffer. __get_snap_name() copies
rde->name / rde->name_len the same unchecked way.

Impact: a malicious or compromised Ceph MDS overflows the NAME_MAX name
buffer in a client's NFS-export get_name path, a slab out-of-bounds write
reported by KASAN. Reachable when a CephFS mount is re-exported over NFS.

Add ceph_export_copy_name(), which rejects lengths above NAME_MAX with
-ENAMETOOLONG before the copy, and use it in both ceph_get_name() and
__get_snap_name().

## Affected Products

- Linux — Linux (19913b4eac4a230dccb548931358398f45dabe4c)
- Linux — Linux (3.15)
- Linux — Linux (0)
- Linux — Linux (6.12.109)
- Linux — Linux (6.18.50)
- Linux — Linux (7.2.4)
- Linux — Linux (7.3-rc1)
- Linux — Linux (6.6.157)

## References

- [CNA](https://git.kernel.org/stable/c/61d9f27b191b838b96b697ce0bfaee39a138243a)
- [CNA](https://git.kernel.org/stable/c/06fb5e623cdc2402d6bb29be94d9beb9a826ffec)
- [CNA](https://git.kernel.org/stable/c/e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6)
- [CNA](https://git.kernel.org/stable/c/eff8013c5a8916613c742ae5a2cc341cb605c0ae)
- [CNA](https://git.kernel.org/stable/c/a294064e0e0f81ea607b2f019e16888aa1b0a011)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.46%
- **EPSS Percentile:** 39.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-19._