CVE-2026-43360Public exploit

Filesystem service interruption via colliding file-name hashes

Published May 8, 2026 · Updated May 8, 2026

Denial of service in Linux kernel Btrfs allows local users to force a mounted filesystem read-only via crafted file names. The directory-item insertion path packs equal CRC32C name hashes into one item, but aborts the transaction when the item reaches the leaf-size limit. Any unprivileged local user with write access to a mounted Btrfs directory can trigger the abort, disrupting writes across that filesystem.

CVSS severity5.5
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux kernel Btrfs allows local users to force a mounted filesystem read-only via crafted file names. The directory-item insertion path packs equal CRC32C name hashes into one item, but aborts the transaction when the item reaches the leaf-size limit. Any unprivileged local user with write access to a mounted Btrfs directory can trigger the abort, disrupting writes across that filesystem.

The record

CVE
CVE-2026-43360
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.19
  2. Affected versionversion=caae78e032343df525b8d05c58b462827f10b2a3 <0625e564290450c1921b115fc3d9abef74e055bd
  3. Affected versionversion=caae78e032343df525b8d05c58b462827f10b2a3 <2d1ababdedd4ba38867c2500eb7f95af5ddeeef7
  4. Affected versionversion=caae78e032343df525b8d05c58b462827f10b2a3 <36947b5200b89bbe3a63629c12d4b31c84c0af9f
  5. Affected versionversion=caae78e032343df525b8d05c58b462827f10b2a3 <5e2ea10b800d1bbb95e0c01a83f4f8119ac5d688
  6. Affected versionversion=caae78e032343df525b8d05c58b462827f10b2a3 <64ad49597d14c495ab8b7933bfefc83936a598e4
  7. Affected versionversion=caae78e032343df525b8d05c58b462827f10b2a3 <9273175bf16c83f3ec93aa242d78c9b5db452d4d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.19; version=caae78e032343df525b8d05c58b462827f10b2a3 <0625e564290450c1921b115fc3d9abef74e055bd; version=caae78e032343df525b8d05c58b462827f10b2a3 <2d1ababdedd4ba38867c2500eb7f95af5ddeeef7; version=caae78e032343df525b8d05c58b462827f10b2a3 <36947b5200b89bbe3a63629c12d4b31c84c0af9f; version=caae78e032343df525b8d05c58b462827f10b2a3 <5e2ea10b800d1bbb95e0c01a83f4f8119ac5d688; version=caae78e032343df525b8d05c58b462827f10b2a3 <64ad49597d14c495ab8b7933bfefc83936a598e4; version=caae78e032343df525b8d05c58b462827f10b2a3 <9273175bf16c83f3ec93aa242d78c9b5db452d4d

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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