19 September 2026
Reference: CVE-2025-39682
1. What is being reported?
The Linux kernel, which is the core part of the Linux operating system, has a flaw in how it processes encrypted data records. This flaw can cause the system to mishandle certain zero-length data packets, which attackers can exploit to compromise security.
2. What this means in plain English
If your organisation uses Linux systems, this flaw could allow attackers to intercept or disrupt secure communications, potentially leading to data breaches or system compromise. This is especially important if your Linux systems handle sensitive information or connect to the internet.
3. Could this affect a small business?
Small businesses or organisations using Linux servers, desktops, or devices that rely on the Linux kernel could be affected. Those not using Linux or only using other operating systems are unlikely to be impacted.
4. What to do now
- Check with your IT provider or software supplier whether your Linux systems are affected by this vulnerability.
- Apply any security updates or patches provided by your Linux vendor as soon as possible.
- If updates are not yet available, follow any recommended mitigations from your vendor or consider temporarily discontinuing use of affected systems connected to the internet.
- Ensure your IT provider evaluates your systems’ exposure to the internet and prioritises patching according to official security guidance.
5. Ask your IT provider
Can you confirm if our Linux systems are affected by CVE-2025-39682 and what steps are being taken to apply the necessary security updates or mitigations?
6. Bottom line
If you use Linux systems, act promptly to update them and protect your organisation from an actively exploited critical security flaw.
Information based on CISA KEV, NVD and reputable security reporting.