Linux: Use After Free
CVE-2026-64178 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 a75bbcb10cb21acc169b785e9804f57d97873a9c, 4907596f25b1720fa948371ac5f6c1f8da10a5bc, 915a92182e2cda9cd7d2479020a44c6eda986f7c 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 0.3% 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 a75bbcb10cb21acc169b785e9804f57d97873a9c or 4907596f25b1720fa948371ac5f6c1f8da10a5bc or 915a92182e2cda9cd7d2479020a44c6eda986f7c or fe69f634b076ae3ca81c5a5b845d9bba527036f7, 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 | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, a75bbcb10cb21acc169b785e9804f57d97873a9c; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 4907596f25b1720fa948371ac5f6c1f8da10a5bc; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 915a92182e2cda9cd7d2479020a44c6eda986f7c; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, fe69f634b076ae3ca81c5a5b845d9bba527036f7; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, b21805258d7e926adfd455fc820a447b90da3b82; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 5506aec795135cdd4cbf4e845929155663b25055; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, e7578529b97e5d4e439cf8f3e637c2303015338f; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 59e932ded949fa6f0340bf7c6d7818f962fa4fd2; and 1 more ranges | a75bbcb10cb21acc169b785e9804f57d97873a9c, 4907596f25b1720fa948371ac5f6c1f8da10a5bc, 915a92182e2cda9cd7d2479020a44c6eda986f7c, fe69f634b076ae3ca81c5a5b845d9bba527036f7, b21805258d7e926adfd455fc820a447b90da3b82, 5506aec795135cdd4cbf4e845929155663b25055 |
| Linux | Linux Kernel | 2.6.12.1 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; 2.6.12; and 1 more ranges | 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: Bluetooth: bnep: Fix UAF read of dev->name bnep_add_connection() needs to keep holding the bnep_session_sem while reading dev->name (just like bnep_get_connlist() does); otherwise the bnep_session() thread can concurrently free the net_device, which can for example be triggered by a concurrent bnep_del_connection(). (This UAF is fairly uninteresting from a security perspective; calling bnep_add_connection() requires passing a capable(CAP_NET_ADMIN) check. It also requires completely tearing down a netdev during a fairly tight race window.)
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.
- 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
- git.kernel.org/stable/c/4907596f25b1720fa948371ac5f6c1f8da10a5bc
- git.kernel.org/stable/c/5506aec795135cdd4cbf4e845929155663b25055
- git.kernel.org/stable/c/59e932ded949fa6f0340bf7c6d7818f962fa4fd2
- git.kernel.org/stable/c/915a92182e2cda9cd7d2479020a44c6eda986f7c
- git.kernel.org/stable/c/a75bbcb10cb21acc169b785e9804f57d97873a9c
- git.kernel.org/stable/c/b21805258d7e926adfd455fc820a447b90da3b82
- git.kernel.org/stable/c/e7578529b97e5d4e439cf8f3e637c2303015338f
- git.kernel.org/stable/c/fe69f634b076ae3ca81c5a5b845d9bba527036f7
Recent Use After Free vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 7.8 High severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
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