Linux: Double Free
CVE-2026-53233 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 e055ca9205d3eb6aec3e5fe4ecc18abbbf18c599, c299321bc6232770ce378d6fa6bc46004d2d7fdb, 9b019376cbee10c4f9184d1745fa37d156e36f30 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 e055ca9205d3eb6aec3e5fe4ecc18abbbf18c599 or c299321bc6232770ce378d6fa6bc46004d2d7fdb or 9b019376cbee10c4f9184d1745fa37d156e36f30 or c849de7d8757a7af801fc4a4058f71d481d367f2, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.94 or 6.18.36 or 7.0.13, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 170aafe35cb98e0f3fbacb446ea86389fbce22ea up to, but not including, e055ca9205d3eb6aec3e5fe4ecc18abbbf18c599; 170aafe35cb98e0f3fbacb446ea86389fbce22ea up to, but not including, c299321bc6232770ce378d6fa6bc46004d2d7fdb; 170aafe35cb98e0f3fbacb446ea86389fbce22ea up to, but not including, 9b019376cbee10c4f9184d1745fa37d156e36f30; 170aafe35cb98e0f3fbacb446ea86389fbce22ea up to, but not including, c849de7d8757a7af801fc4a4058f71d481d367f2; 6.12 | e055ca9205d3eb6aec3e5fe4ecc18abbbf18c599, c299321bc6232770ce378d6fa6bc46004d2d7fdb, 9b019376cbee10c4f9184d1745fa37d156e36f30, c849de7d8757a7af801fc4a4058f71d481d367f2 |
| Linux | Linux Kernel | 6.12 up to, but not including, 6.12.94; 6.13 up to, but not including, 6.18.36; 6.19 up to, but not including, 7.0.13; 7.1 | 6.12.94, 6.18.36, 7.0.13 |
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: netdev: fix double-free in netdev_nl_bind_rx_doit() Sashiko flags that genlmsg_reply() always consumes the skb. The error path calls nlmsg_free(rsp) so we can't jump directly to it. Let's not unbind, just propagate the error to the user. This is the typical way of handling genlmsg_reply() failures. They shouldn't happen unless user does something silly like calling the kernel with an already-full rcvbuf.
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.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Double Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
- 8.8 High severity
- 7.8 High severity
- 8.8 High severity
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