CVE-2025-40186 · cross-distro fix matrix

CVE-2025-40186: In the Linux kernel, the following vulnerability has been resolved: tcp: Don't call reqsk_fastopen_remove() in tcp_conn_request(). syzbot reported the splat below in tcp_conn_request(). [0] If a listener is close()d while a TFO socket is being processed in tcp_conn_request(), inet_csk_reqsk_queue

Affects 3 Linux releases across 4 (distro × package) combinations.

Fix per ecosystem

Each block below is a distro release where CVE-2025-40186 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

linux→ fixed in5.10.247-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y linux
```
linux-6.1→ fixed in6.1.158-1~deb11u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y linux-6.1
```

Debian bookworm

Source: Debian Security Tracker

linux→ fixed in6.1.158-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y linux
```

Debian trixie

Source: Debian Security Tracker

linux→ fixed in6.12.57-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y linux
```

Are YOU affected by CVE-2025-40186?

5-second check on your actual server. Reads /etc/os-release, uname -r, and the distro's package manager; matches against this same cross-source index live.

curl https://mindsparkstack.com/scan.sh | bash

Form-based quickscan View on NVD

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