CVE-2026-2781 · cross-distro fix matrix

CVE-2026-2781: Integer overflow in the Libraries component in NSS. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, Thunderbird 140.8, and Firefox ESR 115.35.

Affects 3 Linux releases across 9 (distro × package) combinations.

Fix per ecosystem

Each block below is a distro release where CVE-2026-2781 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

firefox-esr→ fixed in140.8.0esr-1~deb11u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y firefox-esr
```
nss→ fixed in2:3.61-1+deb11u5urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y nss
```
thunderbird→ fixed in1:140.8.0esr-1~deb11u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y thunderbird
```

Debian bookworm

Source: Debian Security Tracker

firefox-esr→ fixed in140.8.0esr-1~deb12u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y firefox-esr
```
nss→ fixed in2:3.87.1-1+deb12u2urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y nss
```
thunderbird→ fixed in1:140.8.0esr-1~deb12u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y thunderbird
```

Debian trixie

Source: Debian Security Tracker

firefox-esr→ fixed in140.8.0esr-1~deb13u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y firefox-esr
```
nss→ fixed in2:3.110-1+deb13u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y nss
```
thunderbird→ fixed in1:140.8.0esr-1~deb13u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y thunderbird
```

Are YOU affected by CVE-2026-2781?

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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