Linux: Double Free
CVE-2026-64570 is a high-severity double free 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 e2c55079155a953db669ca1986a985fa286bad95, 5baaa1042f71dd4b8e418f2cdd516808702d229b, 1981fba71797ec95e6755fb882cad88899a2a84f 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 0.18% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to e2c55079155a953db669ca1986a985fa286bad95 or 5baaa1042f71dd4b8e418f2cdd516808702d229b or 1981fba71797ec95e6755fb882cad88899a2a84f or 286e52a799fa158bdbd77da1426c4d93f9a6e7ad, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.101 or 6.18.42 or 7.1.6, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 3b1c256eb4aedfc71dd97d5951ccff824b41d628 up to, but not including, e2c55079155a953db669ca1986a985fa286bad95; 3b1c256eb4aedfc71dd97d5951ccff824b41d628 up to, but not including, 5baaa1042f71dd4b8e418f2cdd516808702d229b; 3b1c256eb4aedfc71dd97d5951ccff824b41d628 up to, but not including, 1981fba71797ec95e6755fb882cad88899a2a84f; 3b1c256eb4aedfc71dd97d5951ccff824b41d628 up to, but not including, 286e52a799fa158bdbd77da1426c4d93f9a6e7ad; 6.7 | e2c55079155a953db669ca1986a985fa286bad95, 5baaa1042f71dd4b8e418f2cdd516808702d229b, 1981fba71797ec95e6755fb882cad88899a2a84f, 286e52a799fa158bdbd77da1426c4d93f9a6e7ad |
| Linux | Linux Kernel | 6.7 up to, but not including, 6.12.101; 6.13 up to, but not including, 6.18.42; 6.19 up to, but not including, 7.1.6; 7.2 | 6.12.101, 6.18.42, 7.1.6 |
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 CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix fils_discovery double free on alloc failure ieee80211_set_fils_discovery() calls kfree_rcu() on the old template before allocating the replacement. If the kzalloc() then fails, it returns -ENOMEM while link->u.ap.fils_discovery still points at the object already queued for freeing. A later update or AP teardown (ieee80211_stop_ap()) re-queues that same rcu_head; the second free is caught by KASAN when the RCU sheaf is processed in softirq: BUG: KASAN: double-free in rcu_free_sheaf (mm/slub.c:5850) Free of addr ffff88800c065280 by task swapper/0/0 ... __rcu_free_sheaf_prepare (mm/slub.c:2634 mm/slub.c:2940) rcu_free_sheaf (mm/slub.c:5850) rcu_core (kernel/rcu/tree.c:2617 kernel/rcu/tree.c:2869) handle_softirqs (kernel/softirq.c:622) The buggy address belongs to the cache kmalloc-96 of size 96 Queue the old object for kfree_rcu() only after the new one is published, matching ieee80211_set_probe_resp() and ieee80211_set_s1g_short_beacon().
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Double Free
The product calls free() twice on the same memory address.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
- Use a static analysis tool to find double free instances.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Double Free vulnerabilities
- 7.8 High severity
- 8.7 High severity
- 9.8 Critical severity
- 7.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
Spotted an error? Tell us.