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CVE-2026-23141 Linux CVE debrief

A vulnerability in the Linux kernel's Btrfs filesystem send functionality could allow invalid memory access when processing inline extents. The issue occurs in range_is_hole_in_parent() where the disk_bytenr field of a file extent item is accessed without first verifying whether the extent is inline. For inline extents, data begins at the offset of the disk_bytenr field, meaning accessing this field reads inline data rather than a disk address. If inline data is smaller than 8 bytes, this can cause invalid memory access when the inline extent item is the first item in a leaf, or result in reading metadata from other items. The vulnerability is local, requires low privileges, and can lead to denial of service through system crash.

Vendor
Linux
Product
Unknown
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-02-14
Original CVE updated
2026-06-01
Advisory published
2026-02-14
Advisory updated
2026-06-01

Who should care

Linux system administrators running Btrfs filesystems with send/receive functionality enabled; organizations using Btrfs for backups or replication; kernel maintainers and distribution security teams responsible for stable kernel updates

Technical summary

The Btrfs send feature in the Linux kernel contains a flaw in range_is_hole_in_parent() where file extent items are processed without checking for inline extents. Inline extents store data directly in the file extent item structure, with data starting at the disk_bytenr field offset. When code treats this field as a disk block address rather than inline data, it can read incorrect data or cause out-of-bounds memory access. If the inline extent is the first item in a Btrfs leaf and contains fewer than 8 bytes, the access can extend beyond valid memory boundaries. This is a local vulnerability exploitable by users with permissions to perform Btrfs send operations, resulting in potential system crash (denial of service). The fix adds proper inline extent detection before accessing disk_bytenr.

Defensive priority

medium

Recommended defensive actions

  • Apply the appropriate stable kernel patch for your affected version stream (4.11+, 6.7+, 6.13+, or 6.19-rc series)
  • Upgrade to a fixed kernel version: 6.6.122 or later, 6.12.67 or later, 6.18.7 or later, or 6.19-rc6 or later
  • If immediate patching is not possible, restrict untrusted local access to Btrfs send operations
  • Monitor kernel logs for unexpected crashes during Btrfs send operations as potential indicators of exploitation attempts

Evidence notes

The CVE description and NVD metadata confirm this is a resolved Linux kernel vulnerability in Btrfs send operations. Multiple stable kernel patches are available. The CVSS 3.1 vector AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H indicates local attack vector with low attack complexity, low privileges required, no user interaction, and high availability impact. Affected versions span Linux kernel 4.11 through 6.6.121, 6.7 through 6.12.66, 6.13 through 6.18.6, and 6.19-rc1 through 6.19-rc5.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-23141 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-23141

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

  • CVE-2026-23141 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-23141

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

Supplemental references

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/08b096c1372cd69627f4f559fb47c9fb67a52b39

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

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/39f83f10772310ba4a77f2b5256aaf36994ef7e8

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/901e581bfc44d181f7d9c3f11880dac3e89deb2e

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/d948055bd46a9c14d1d4217aed65c5c258c32903

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

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/db00636643e66898d79f2530ac9c56ebd5eca369

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

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/f2dc6ab3a14c2d2eb0b14783427eb9b03bf631c9

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

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.