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CVE-2026-23201

N/A Unknown
Denial of Service

📋 TL;DR

A memory management vulnerability in the Linux kernel's Ceph filesystem driver causes a kernel oops (crash) when accessing snapshot directories. This affects systems using CephFS with snapshots, potentially leading to denial of service. The issue occurs due to incorrect pointer arithmetic in the parse_longname() function.

💻 Affected Systems

Products:
  • Linux kernel with CephFS support
Versions: Kernel versions containing vulnerable CephFS code (specific versions not provided in CVE)
Operating Systems: Linux distributions with CephFS support
Default Config Vulnerable: ⚠️ Yes
Notes: Only affects systems with CephFS mounts that have snapshots. Requires accessing the .snap directory to trigger.

⚠️ Manual Verification Required

This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.

Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).

🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.

Recommended Actions:
  1. Review the CVE details at NVD
  2. Check vendor security advisories for your specific version
  3. Test if the vulnerability is exploitable in your environment
  4. Consider updating to the latest version as a precaution

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and complete denial of service, requiring physical or remote console access to reboot.

🟠

Likely Case

System becomes unresponsive when accessing CephFS snapshot directories, requiring reboot to restore functionality.

🟢

If Mitigated

No impact if CephFS snapshots are not accessed or the system is patched.

🌐 Internet-Facing: LOW - Requires local filesystem access to trigger, not network exploitable.
🏢 Internal Only: MEDIUM - Local users or automated processes accessing CephFS snapshots can crash the system.

🎯 Exploit Status

Public PoC: ✅ No
Weaponized: UNKNOWN
Unauthenticated Exploit: ✅ No
Complexity: LOW

Exploitation requires local access to trigger via simple commands like 'ls' on snapshot directories.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing commits 8c9af7339de4, bc8dedae022c, or e258ed369c9e

Vendor Advisory: https://git.kernel.org/stable/c/8c9af7339de419819cfc641d551675d38ff99abf

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution. 2. Reboot system to load new kernel. 3. Verify kernel version matches patched release.

🔧 Temporary Workarounds

Avoid accessing CephFS snapshots

all

Prevent users and processes from accessing CephFS .snap directories

# Set permissions to restrict access
chmod 000 /mnt/ceph_mount/.snap
# Or unmount CephFS volumes
umount /mnt/ceph_mount

🧯 If You Can't Patch

  • Restrict access to CephFS mount points to trusted users only
  • Disable or remove CephFS snapshots until system can be patched

🔍 How to Verify

Check if Vulnerable:

Check if system has CephFS mounts with snapshots: 'mount | grep ceph' and test 'ls /mountpoint/.snap'

Check Version:

uname -r

Verify Fix Applied:

After patching, verify kernel version and test accessing CephFS snapshot directories without system crash

📡 Detection & Monitoring

Log Indicators:

  • Kernel oops messages in /var/log/kern.log or dmesg
  • System crash/panic logs
  • Processes hanging when accessing CephFS

Network Indicators:

  • No network indicators - local filesystem issue

SIEM Query:

search 'kernel: BUG:' OR 'kernel: Oops:' OR 'kernel: general protection fault' AND 'ceph' OR 'parse_longname'

📊 Metadata

CVE ID: CVE-2026-23201
CVSS v3 Score: N/A (Unknown)
Published: February 14, 2026
Last Updated: February 18, 2026

🔗 References

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