CVE-2025-39849 wifi: cfg80211: sme: cap SSID length in __cfg80211_connect_result()
A missing bounds check in the Linux kernel Wi-Fi subsystem allows memory corruption via oversized SSIDs, potentially leading to code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-39849?
CVE-2025-39849 is a high-severity memory corruption vulnerability in Debian Debian Linux, published on 19 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: sme: cap SSID length in __cfg80211_connect_result()
If the ssid->datalen is more than IEEE80211_MAX_SSID_LEN (32) it would lead to memory corruption so add some bounds checking.
Weakness: CWE-787
Which versions are affected by CVE-2025-39849?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-39849?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-39849 being exploited?
There is no known exploitation of CVE-2025-39849 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-67520, BELL-CVE-2025-39849, DEBIAN-CVE-2025-39849, GHSA-wfxg-5hf2-j2vg, ROOT-OS-UBUNTU-2404-CVE-2025-39849, UBUNTU-CVE-2025-39849.