CyberSecBulletin
CVE-2026-53388NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-53388 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 7c18691e0cfda29672f79bafde8abdb7710674f6, 5927b43a4f8d89e86930f524bf63e9c7e66f61b4, 030fe3e9d8abdee303dd7e9e42f45082d382a407 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.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 7c18691e0cfda29672f79bafde8abdb7710674f6 or 5927b43a4f8d89e86930f524bf63e9c7e66f61b4 or 030fe3e9d8abdee303dd7e9e42f45082d382a407 or 46473ddccdc5065033e397d6e62c280dbcd3d9c2, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.15.211 or 6.1.177 or 6.6.144 or 6.12.95, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxce534fb052928ce556639d7ecf01cbf4e01321e1 up to, but not including, 7c18691e0cfda29672f79bafde8abdb7710674f6; ce534fb052928ce556639d7ecf01cbf4e01321e1 up to, but not including, 5927b43a4f8d89e86930f524bf63e9c7e66f61b4; ce534fb052928ce556639d7ecf01cbf4e01321e1 up to, but not including, 030fe3e9d8abdee303dd7e9e42f45082d382a407; ce534fb052928ce556639d7ecf01cbf4e01321e1 up to, but not including, 46473ddccdc5065033e397d6e62c280dbcd3d9c2; ce534fb052928ce556639d7ecf01cbf4e01321e1 up to, but not including, af2892249d982a1c036ca456cc135374e68b6677; ce534fb052928ce556639d7ecf01cbf4e01321e1 up to, but not including, 0223f452532d9cd8a5e87c45de828fd93c99bd25; ce534fb052928ce556639d7ecf01cbf4e01321e1 up to, but not including, e28db6ac4792d065ab32565fd9f0a2361c3d4666; ce534fb052928ce556639d7ecf01cbf4e01321e1 up to, but not including, a078484921052d0badd827fcc2770b5cfc1d4120; and 1 more ranges7c18691e0cfda29672f79bafde8abdb7710674f6, 5927b43a4f8d89e86930f524bf63e9c7e66f61b4, 030fe3e9d8abdee303dd7e9e42f45082d382a407, 46473ddccdc5065033e397d6e62c280dbcd3d9c2, af2892249d982a1c036ca456cc135374e68b6677, 0223f452532d9cd8a5e87c45de828fd93c99bd25
LinuxLinux Kernel2.6.35 up to, but not including, 5.15.211; 5.16 up to, but not including, 6.1.177; 6.2 up to, but not including, 6.6.144; 6.7 up to, but not including, 6.12.95; 6.13 up to, but not including, 6.18.37; 6.19 up to, but not including, 7.0.14; 7.1 up to, but not including, 7.1.25.15.211, 6.1.177, 6.6.144, 6.12.95, 6.18.37, 7.0.14

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: fuse: re-lock request before replacing page cache folio fuse_try_move_folio() unlocks the request on entry but does not re-lock it on the success path. This means fuse_chan_abort() can end the request and free the fuse_io_args (eg fuse_readpages_end()) while the subsequent copy chain logic after fuse_try_move_folio() accesses the fuse_io_args, leading to use-after-free issues. Fix this by calling lock_request() before replace_page_cache_folio(). This ensures the request is locked on the success path which will prevent the fuse_io_args from being freed while the later copying logic runs, and also ensures that the ap->folios[i]->mapping is never null since ap->folios[i] will always point to the newfolio after replace_page_cache_folio().

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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