CyberSecBulletin
CVE-2026-64446NVD status: Analyzed

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-64446 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions a94a643a80a84ceb8139061c3d6bf988d75e45a5, 2131621986c62c86109ce4d84cf73a73757eb8a6, 6f20d7b0ee47c470734a69379b0fc6647c519603 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.14% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to a94a643a80a84ceb8139061c3d6bf988d75e45a5 or 2131621986c62c86109ce4d84cf73a73757eb8a6 or 6f20d7b0ee47c470734a69379b0fc6647c519603 or 5d7812360abf3143afcbf5efe4ef242448fa1f28, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.261 or 5.15.212 or 6.1.178 or 6.6.145, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux554c0a3abf216c991c5ebddcdb2c08689ecd290b up to, but not including, a94a643a80a84ceb8139061c3d6bf988d75e45a5; 554c0a3abf216c991c5ebddcdb2c08689ecd290b up to, but not including, 2131621986c62c86109ce4d84cf73a73757eb8a6; 554c0a3abf216c991c5ebddcdb2c08689ecd290b up to, but not including, 6f20d7b0ee47c470734a69379b0fc6647c519603; 554c0a3abf216c991c5ebddcdb2c08689ecd290b up to, but not including, 5d7812360abf3143afcbf5efe4ef242448fa1f28; 554c0a3abf216c991c5ebddcdb2c08689ecd290b up to, but not including, 46f66c16a95191d9aca07a72ae6b1252a244e26c; 554c0a3abf216c991c5ebddcdb2c08689ecd290b up to, but not including, b9c4bf133c3c47e23baf4f5403b98a953bf58606; 554c0a3abf216c991c5ebddcdb2c08689ecd290b up to, but not including, 138cd190efd56ab36c9fdd8fef8749d06937f24b; 554c0a3abf216c991c5ebddcdb2c08689ecd290b up to, but not including, 5a752a616e756844388a1a45404db9fc29fec655; and 1 more rangesa94a643a80a84ceb8139061c3d6bf988d75e45a5, 2131621986c62c86109ce4d84cf73a73757eb8a6, 6f20d7b0ee47c470734a69379b0fc6647c519603, 5d7812360abf3143afcbf5efe4ef242448fa1f28, 46f66c16a95191d9aca07a72ae6b1252a244e26c, b9c4bf133c3c47e23baf4f5403b98a953bf58606
LinuxLinux Kernel4.12 up to, but not including, 5.10.261; 5.11 up to, but not including, 5.15.212; 5.16 up to, but not including, 6.1.178; 6.2 up to, but not including, 6.6.145; 6.7 up to, but not including, 6.12.96; 6.13 up to, but not including, 6.18.39; 6.19 up to, but not including, 7.1.4; 7.25.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix heap buffer overflow in rtw_cfg80211_set_wpa_ie() supplicant_ie is a 256-byte array in struct security_priv. The WPA and WPA2 IE copy paths use: memcpy(padapter->securitypriv.supplicant_ie, &pwpa[0], wpa_ielen + 2); where wpa_ielen is the raw IE length field (u8, 0-255). When a local user supplies a connect request via nl80211 with a crafted WPA IE of length 255, wpa_ielen + 2 equals 257, overflowing the 256-byte buffer by one byte into the adjacent last_mic_err_time field. rtw_parse_wpa_ie() does not prevent this: its length consistency check compares *(wpa_ie+1) against (u8)(wpa_ie_len-2), which is (u8)(255) == 255 when wpa_ie_len = 257, so the check passes silently. Add explicit bounds checks for both the WPA and WPA2 paths before the memcpy, rejecting any IE whose total size (wpa_ielen + 2) exceeds the supplicant_ie buffer.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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