Linux: Use After Free
CVE-2026-64408 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 390b5db3ff8745187f094c4e915663b7b1f98944, 46a88784c4c9b96954dd86f747ce93f65efa1302, 551ae773ec64045b4e72099132654887e0270bcc 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 390b5db3ff8745187f094c4e915663b7b1f98944 or 46a88784c4c9b96954dd86f747ce93f65efa1302 or 551ae773ec64045b4e72099132654887e0270bcc or ae215c5b6422d8eda443b861b124bd1be6969c31, whichever matches your release line, or a later version.
- 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
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 65f53e9802dbfae0e5758a91793c3f5f8bece49b up to, but not including, 390b5db3ff8745187f094c4e915663b7b1f98944; 65f53e9802dbfae0e5758a91793c3f5f8bece49b up to, but not including, 46a88784c4c9b96954dd86f747ce93f65efa1302; 65f53e9802dbfae0e5758a91793c3f5f8bece49b up to, but not including, 551ae773ec64045b4e72099132654887e0270bcc; 65f53e9802dbfae0e5758a91793c3f5f8bece49b up to, but not including, ae215c5b6422d8eda443b861b124bd1be6969c31; 65f53e9802dbfae0e5758a91793c3f5f8bece49b up to, but not including, df22adc7eafc22e651561813c11dc51a796b12ee; 65f53e9802dbfae0e5758a91793c3f5f8bece49b up to, but not including, a6b22dbd80926556290ad2243be25218d6956a19; 65f53e9802dbfae0e5758a91793c3f5f8bece49b up to, but not including, 563a8573047182f550b1e1e030615755cd8c41da; 65f53e9802dbfae0e5758a91793c3f5f8bece49b up to, but not including, bb067a99a0356196c0b89a95721985485ebce5a5; and 1 more ranges | 390b5db3ff8745187f094c4e915663b7b1f98944, 46a88784c4c9b96954dd86f747ce93f65efa1302, 551ae773ec64045b4e72099132654887e0270bcc, ae215c5b6422d8eda443b861b124bd1be6969c31, df22adc7eafc22e651561813c11dc51a796b12ee, a6b22dbd80926556290ad2243be25218d6956a19 |
| Linux | Linux Kernel | 3.13 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; 7.2 | 5.10.261, 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
- 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: pin L2CAP connection during netdev registration bnep_add_connection() reads the L2CAP connection without holding the channel lock, then passes its HCI device to register_netdev(). Controller teardown can clear and release that connection concurrently, leaving the network device registration path to dereference a freed parent device. Take a reference to the L2CAP connection while holding the channel lock. Retain it until register_netdev() has taken the parent device reference.
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/390b5db3ff8745187f094c4e915663b7b1f98944
- git.kernel.org/stable/c/46a88784c4c9b96954dd86f747ce93f65efa1302
- git.kernel.org/stable/c/551ae773ec64045b4e72099132654887e0270bcc
- git.kernel.org/stable/c/563a8573047182f550b1e1e030615755cd8c41da
- git.kernel.org/stable/c/a6b22dbd80926556290ad2243be25218d6956a19
- git.kernel.org/stable/c/ae215c5b6422d8eda443b861b124bd1be6969c31
- git.kernel.org/stable/c/bb067a99a0356196c0b89a95721985485ebce5a5
- git.kernel.org/stable/c/df22adc7eafc22e651561813c11dc51a796b12ee
Recent Use After Free vulnerabilities
- 9.8 Critical severity
- 7.8 High severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.