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CVE-2026-53388 Linux CVE debrief

A use-after-free vulnerability was found in the Linux kernel's fuse subsystem. The issue arises from fuse_try_move_folio() unlocking the request on entry but failing to re-lock it on the success path. This allows fuse_chan_abort() to end the request and free the fuse_io_args while the subsequent copy chain logic accesses the fuse_io_args, leading to use-after-free issues. The fix involves calling lock_request() before replace_page_cache_folio() to ensure the request remains locked on the success path.

Vendor
Linux
Product
Unknown
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-19
Original CVE updated
2026-08-17
Advisory published
2026-07-19
Advisory updated
2026-08-17

Who should care

Linux kernel developers and maintainers, Linux distribution vendors, and users of Linux-based systems should be aware of this vulnerability and its potential impact on system stability and security.

Technical summary

The vulnerability is caused by a missing lock in the fuse_try_move_folio() function. When fuse_try_move_folio() unlocks the request on entry but does not re-lock it on the success path, it creates a window for fuse_chan_abort() to end the request and free the fuse_io_args. This can lead to use-after-free issues when the subsequent copy chain logic accesses the fuse_io_args. The fix ensures that the request is re-locked before replacing the page cache folio, preventing the fuse_io_args from being freed prematurely.

Defensive priority

Medium

Recommended defensive actions

  • Review and apply the provided kernel patches to ensure the fuse subsystem is properly locking requests.
  • Monitor Linux kernel updates and apply patches promptly.
  • Consider implementing additional monitoring and logging to detect potential exploitation attempts.
  • Perform a thorough review of system configurations and asset inventories to identify potential exposures.
  • Establish a rollback change window to minimize downtime in case of patch application issues.
  • Track and verify the effectiveness of implemented compensating controls.
  • Implement source tracking to monitor for similar vulnerabilities in the future.

Evidence notes

The CVE record was published on 2026-07-19T12:16:49.757Z and has not been modified since then. The NVD entry is currently Received. Multiple source references are provided, including kernel.org links to specific commits.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-53388 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-53388

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-53388 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-53388

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/0223f452532d9cd8a5e87c45de828fd93c99bd25

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/030fe3e9d8abdee303dd7e9e42f45082d382a407

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/46473ddccdc5065033e397d6e62c280dbcd3d9c2

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/5927b43a4f8d89e86930f524bf63e9c7e66f61b4

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/7c18691e0cfda29672f79bafde8abdb7710674f6

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/a078484921052d0badd827fcc2770b5cfc1d4120

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/af2892249d982a1c036ca456cc135374e68b6677

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.