CVE-2025-39891

CVE-2025-39891 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mwifiex: Initialize the chan_stats array to zero The adapter->chan_stats[] array is initialized in mwifiex_init_channel_scan_gap() with vmalloc(), which doesn't zero out memory. The array is filled in mwifiex_update_chan_statistics() and then the user can query the data in mwifiex_cfg80211_dump_survey(). There are two potential issues here. What if the user calls mwifiex_cfg80211_dump_survey() before the data has been filled in. Also the mwifiex_update_chan_statistics() function doesn't necessarily initialize the whole array. Since the array was not initialized at the start that could result in an information leak. Also this array is pretty small. It's a maximum of 900 bytes so it's more appropriate to use kcalloc() instead vmalloc().

Frequently asked questions

What is CVE-2025-39891?
In the Linux kernel, the following vulnerability has been resolved: wifi: mwifiex: Initialize the chan_stats array to zero The adapter->chan_stats[] array is initialized in mwifiex_init_channel_scan_gap() with vmalloc(), which doesn't zero out memory. The array is filled in mwifiex_update_chan_statistics() and then the user can query the data in mwifiex_cfg80211_dump_survey(). There are two potential issues here. What if the user calls mwifiex_cfg80211_dump_survey() before the data has been filled in. Also the mwifiex_update_chan_statistics() function doesn't necessarily initialize the whole array. Since the array was not initialized at the start that could result in an information leak. Also this array is pretty small. It's a maximum of 900 bytes so it's more appropriate to use kcalloc() instead vmalloc().
How severe is CVE-2025-39891?
CVE-2025-39891 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2025-39891 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-39891?
CVE-2025-39891 primarily affects Linux Linux Kernel. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-39891?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-39891 have an EU (EUVD) identifier?
Yes. CVE-2025-39891 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-32904.
When was CVE-2025-39891 published?
CVE-2025-39891 was published on 2025-10-01 and last updated on 2026-06-17.

References

Affected products (6)

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