CVE-2026-45897

Counter underflow via concurrent reset race

Published May 27, 2026 · Updated May 27, 2026

Race condition in Linux Kernel nft_counter reset handling allows local users to corrupt counter accounting through concurrent resets. The reset path fetches a shared total before subtraction without serializing the combined operation, allowing parallel resets to read and subtract the same value and underflow the counter. Exploitation requires local privileges sufficient to invoke parallel netfilter dump-and-reset operations; published sources identify no specific hang, crash, or reboot outcome.

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

Race condition in Linux Kernel nft_counter reset handling allows local users to corrupt counter accounting through concurrent resets. The reset path fetches a shared total before subtraction without serializing the combined operation, allowing parallel resets to read and subtract the same value and underflow the counter. Exploitation requires local privileges sufficient to invoke parallel netfilter dump-and-reset operations; published sources identify no specific hang, crash, or reboot outcome.

The record

CVE
CVE-2026-45897
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=3cb03edb4de33fd04c4ea55f47397b96a8657c53 <0cdc6d5a26f2d1f7f15a43526841b679445c32e2
  2. Affected versionversion=3cb03edb4de33fd04c4ea55f47397b96a8657c53 <779c60a5190c42689534172f4b49e927c9959e4e
  3. Affected versionversion=6.1.107 <6.2
  4. Affected versionversion=6.6.48 <6.7
  5. Affected versionversion=6.7
  6. Affected versionversion=f123293db16dcd0cd81b246ae60e6362f0025d0a
  7. Affected versionversion=fb1adb05ea87b6149e65a31e511756c4f470d0cd

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3cb03edb4de33fd04c4ea55f47397b96a8657c53 <0cdc6d5a26f2d1f7f15a43526841b679445c32e2; version=3cb03edb4de33fd04c4ea55f47397b96a8657c53 <779c60a5190c42689534172f4b49e927c9959e4e; version=6.1.107 <6.2; version=6.6.48 <6.7; version=6.7; version=f123293db16dcd0cd81b246ae60e6362f0025d0a; version=fb1adb05ea87b6149e65a31e511756c4f470d0cd

Published CVSS scores

5.5NIST NVDCVSS: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 exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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