CVE-2025-39864 wifi: cfg80211: fix use-after-free in cmp_bss()

What is CVE-2025-39864?

CVE-2025-39864 is a high-severity use after free 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: fix use-after-free in cmp_bss()

Following bss_free() quirk introduced in commit 776b3580178f ("cfg80211: track hidden SSID networks properly"), adjust cfg80211_update_known_bss() to free the last beacon frame elements only if they're not shared via the corresponding 'hidden_beacon_bss' pointer.

Weakness: CWE-416

Which versions are affected by CVE-2025-39864?

It affects 2 products.

Products include Debian Debian Linux, Linux kernel.

How do I fix CVE-2025-39864?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2025-39864 being exploited?

There is no known exploitation of CVE-2025-39864 in the wild and no public exploit code.

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All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-67575, AZL-74921, BELL-CVE-2025-39864, DEBIAN-CVE-2025-39864, GHSA-mrpv-wrf5-7wr6, ROOT-OS-DEBIAN-11-CVE-2025-39864 and 5 more.