Linux: Use After Free
CVE-2026-64096 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions ff3a4487ead475e27b43280b8ee3d8464fe280e1, 78a63fb2f7d5630d1c1f2859a20d4e4226863b41, ced48f55bac73f0822eae90509e51b42b4f646c8 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 0.26% 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 ff3a4487ead475e27b43280b8ee3d8464fe280e1 or 78a63fb2f7d5630d1c1f2859a20d4e4226863b41 or ced48f55bac73f0822eae90509e51b42b4f646c8 or 70bcb678561f0fb58f33270fc73f12f3be72b878, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.258 or 5.15.209 or 6.1.175 or 6.6.142, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | ab49886e3da73b6b35ece21006e191910427bb30 up to, but not including, ff3a4487ead475e27b43280b8ee3d8464fe280e1; ab49886e3da73b6b35ece21006e191910427bb30 up to, but not including, 78a63fb2f7d5630d1c1f2859a20d4e4226863b41; ab49886e3da73b6b35ece21006e191910427bb30 up to, but not including, ced48f55bac73f0822eae90509e51b42b4f646c8; ab49886e3da73b6b35ece21006e191910427bb30 up to, but not including, 70bcb678561f0fb58f33270fc73f12f3be72b878; ab49886e3da73b6b35ece21006e191910427bb30 up to, but not including, aef897c9d2dd0d9339167fb82b62beff68d076cb; ab49886e3da73b6b35ece21006e191910427bb30 up to, but not including, 8a3707653ab658e082ccd992e92594e01b09a3fc; ab49886e3da73b6b35ece21006e191910427bb30 up to, but not including, edfb1e094104a50f931553dc82ac59246569fd32; ab49886e3da73b6b35ece21006e191910427bb30 up to, but not including, 20c2d6a20ca936f5aaa6dd40f73f262ac45c87cc; and 1 more ranges | ff3a4487ead475e27b43280b8ee3d8464fe280e1, 78a63fb2f7d5630d1c1f2859a20d4e4226863b41, ced48f55bac73f0822eae90509e51b42b4f646c8, 70bcb678561f0fb58f33270fc73f12f3be72b878, aef897c9d2dd0d9339167fb82b62beff68d076cb, 8a3707653ab658e082ccd992e92594e01b09a3fc |
| Linux | Linux Kernel | 3.15 up to, but not including, 5.10.258; 5.11 up to, but not including, 5.15.209; 5.16 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.142; 6.7 up to, but not including, 6.12.92; 6.13 up to, but not including, 6.18.34; 6.19 up to, but not including, 7.0.11; 7.1 | 5.10.258, 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34 |
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
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- 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:A/AC:L/PR:N/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: batman-adv: mcast: fix use-after-free in orig_node RCU release batadv_mcast_purge_orig() removes entries from RCU-protected hlists but does not wait for an RCU grace period before returning. Concurrent RCU readers may still accesses references to those entries at the point of removal. RCU-protected readers trying to operate on entries like orig->mcast_want_all_ipv6_node will then access already freed memory. Fix this by moving batadv_mcast_purge_orig() to batadv_orig_node_release(), just before the call_rcu() invocation. This ensures RCU readers that were active at purge time have drained before the orig_node memory is reclaimed.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/20c2d6a20ca936f5aaa6dd40f73f262ac45c87cc
- git.kernel.org/stable/c/70bcb678561f0fb58f33270fc73f12f3be72b878
- git.kernel.org/stable/c/78a63fb2f7d5630d1c1f2859a20d4e4226863b41
- git.kernel.org/stable/c/8a3707653ab658e082ccd992e92594e01b09a3fc
- git.kernel.org/stable/c/aef897c9d2dd0d9339167fb82b62beff68d076cb
- git.kernel.org/stable/c/ced48f55bac73f0822eae90509e51b42b4f646c8
- git.kernel.org/stable/c/edfb1e094104a50f931553dc82ac59246569fd32
- git.kernel.org/stable/c/ff3a4487ead475e27b43280b8ee3d8464fe280e1
Recent Use After Free vulnerabilities
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.8 High severity
- 9.8 Critical severity
- 8.8 High severity
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