CyberSecBulletin
CVE-2025-38618NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2025-38618 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 c04a2c1ca25b9b23104124d3b2d349d934e302de, d1a5b1964cef42727668ac0d8532dae4f8c19386, cf86704798c1b9c46fa59dfc2d662f57d1394d79 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 0.2% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to c04a2c1ca25b9b23104124d3b2d349d934e302de or d1a5b1964cef42727668ac0d8532dae4f8c19386 or cf86704798c1b9c46fa59dfc2d662f57d1394d79 or f138be5d7f301fddad4e65ec66dfc3ceebf79be3, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.4.297 or 5.10.241 or 5.15.190 or 6.1.148, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxd021c344051af91f42c5ba9fdedc176740cbd238 up to, but not including, c04a2c1ca25b9b23104124d3b2d349d934e302de; d021c344051af91f42c5ba9fdedc176740cbd238 up to, but not including, d1a5b1964cef42727668ac0d8532dae4f8c19386; d021c344051af91f42c5ba9fdedc176740cbd238 up to, but not including, cf86704798c1b9c46fa59dfc2d662f57d1394d79; d021c344051af91f42c5ba9fdedc176740cbd238 up to, but not including, f138be5d7f301fddad4e65ec66dfc3ceebf79be3; d021c344051af91f42c5ba9fdedc176740cbd238 up to, but not including, 44bd006d5c93f6a8f28b106cbae2428c5d0275b7; d021c344051af91f42c5ba9fdedc176740cbd238 up to, but not including, 32950b1907919be86a7a2697d6f93d57068b3865; d021c344051af91f42c5ba9fdedc176740cbd238 up to, but not including, 8f01093646b49f6330bb2d36761983fd829472b1; d021c344051af91f42c5ba9fdedc176740cbd238 up to, but not including, d73960f0cf03ef1dc9e96ec7a20e538accc26d87; and 2 more rangesc04a2c1ca25b9b23104124d3b2d349d934e302de, d1a5b1964cef42727668ac0d8532dae4f8c19386, cf86704798c1b9c46fa59dfc2d662f57d1394d79, f138be5d7f301fddad4e65ec66dfc3ceebf79be3, 44bd006d5c93f6a8f28b106cbae2428c5d0275b7, 32950b1907919be86a7a2697d6f93d57068b3865
LinuxLinux Kernel3.9 up to, but not including, 5.4.297; 5.5 up to, but not including, 5.10.241; 5.11 up to, but not including, 5.15.190; 5.16 up to, but not including, 6.1.148; 6.2 up to, but not including, 6.6.102; 6.7 up to, but not including, 6.12.42; 6.13 up to, but not including, 6.15.10; 6.16 up to, but not including, 6.16.1; and 1 more ranges5.4.297, 5.10.241, 5.15.190, 6.1.148, 6.6.102, 6.12.42
DebianDebian Linux11.0Not stated

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.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: vsock: Do not allow binding to VMADDR_PORT_ANY It is possible for a vsock to autobind to VMADDR_PORT_ANY. This can cause a use-after-free when a connection is made to the bound socket. The socket returned by accept() also has port VMADDR_PORT_ANY but is not on the list of unbound sockets. Binding it will result in an extra refcount decrement similar to the one fixed in fcdd2242c023 (vsock: Keep the binding until socket destruction). Modify the check in __vsock_bind_connectible() to also prevent binding to VMADDR_PORT_ANY.

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.

More Use After Free vulnerabilities (CWE-416)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use After Free vulnerabilities

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