Linux: Use After Free
CVE-2026-64002 is a high-severity use after 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 ecf45080a4d3f4526cacb8b14060fe3b49a6913b, a0ffc6081a8b27082dd5eae5aa1e3f59bbecf06c, 5b23a2ff379e70b6b9ff744a972b63e1f8f4d996 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 0.13% 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 ecf45080a4d3f4526cacb8b14060fe3b49a6913b or a0ffc6081a8b27082dd5eae5aa1e3f59bbecf06c or 5b23a2ff379e70b6b9ff744a972b63e1f8f4d996 or 8e59d4d0dcde2dfb07a7ef855c849a2a0560aa57, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.259 or 5.15.210 or 6.1.176 or 6.6.143, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 122ff243f5f104194750ecbc76d5946dd1eec934 up to, but not including, ecf45080a4d3f4526cacb8b14060fe3b49a6913b; 122ff243f5f104194750ecbc76d5946dd1eec934 up to, but not including, a0ffc6081a8b27082dd5eae5aa1e3f59bbecf06c; 122ff243f5f104194750ecbc76d5946dd1eec934 up to, but not including, 5b23a2ff379e70b6b9ff744a972b63e1f8f4d996; 122ff243f5f104194750ecbc76d5946dd1eec934 up to, but not including, 8e59d4d0dcde2dfb07a7ef855c849a2a0560aa57; 122ff243f5f104194750ecbc76d5946dd1eec934 up to, but not including, 6512c57c4638ddec113bf42439361ba85a12048d; 122ff243f5f104194750ecbc76d5946dd1eec934 up to, but not including, a7f4eefb6e1458431eef9fa20fb363320d185f76; 122ff243f5f104194750ecbc76d5946dd1eec934 up to, but not including, 155f90be5ee8be5b110ebc0b7da33c54c83b0208; 122ff243f5f104194750ecbc76d5946dd1eec934 up to, but not including, 87a1e0fe7776da7ab411be332b4be58ac8840d10; and 1 more ranges | ecf45080a4d3f4526cacb8b14060fe3b49a6913b, a0ffc6081a8b27082dd5eae5aa1e3f59bbecf06c, 5b23a2ff379e70b6b9ff744a972b63e1f8f4d996, 8e59d4d0dcde2dfb07a7ef855c849a2a0560aa57, 6512c57c4638ddec113bf42439361ba85a12048d, a7f4eefb6e1458431eef9fa20fb363320d185f76 |
| Linux | Linux Kernel | 3.16 up to, but not including, 5.10.259; 5.11 up to, but not including, 5.15.210; 5.16 up to, but not including, 6.1.176; 6.2 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.93; 6.13 up to, but not including, 6.18.35; 6.19 up to, but not including, 7.0.12; 7.1 | 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35 |
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: ipv4: free net->ipv4.sysctl_local_reserved_ports after unregister_net_sysctl_table() ipv4_sysctl_exit_net() is currently freeing net->ipv4.sysctl_local_reserved_ports too soon. Only after unregister_net_sysctl_table() we can be sure no threads can possibly use the sysctls, including /proc/sys/net/ipv4/ip_local_reserved_ports.
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/155f90be5ee8be5b110ebc0b7da33c54c83b0208
- git.kernel.org/stable/c/5b23a2ff379e70b6b9ff744a972b63e1f8f4d996
- git.kernel.org/stable/c/6512c57c4638ddec113bf42439361ba85a12048d
- git.kernel.org/stable/c/87a1e0fe7776da7ab411be332b4be58ac8840d10
- git.kernel.org/stable/c/8e59d4d0dcde2dfb07a7ef855c849a2a0560aa57
- git.kernel.org/stable/c/a0ffc6081a8b27082dd5eae5aa1e3f59bbecf06c
- git.kernel.org/stable/c/a7f4eefb6e1458431eef9fa20fb363320d185f76
- git.kernel.org/stable/c/ecf45080a4d3f4526cacb8b14060fe3b49a6913b
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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