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Response snapshot Nov 8, 2026, 22:35 UTC

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VulnerabilityCVE-2026-64251

Linux kernel: pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next()

In the Linux kernel, the following vulnerability has been resolved: pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next() pwrseq_debugfs_seq_next() declares 'next' with __free(put_device), which causes put_device() to be called on the returned pointer when the variable goes out of scope.

At a glance

Exploited
Not known
Severity
7.8 High (CVSS 3.1)
Chance of exploitation
0.2% in the next 30 days
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-64251 (opens a new tab)

What happened

In the Linux kernel, the following vulnerability has been resolved:

pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next()

pwrseq_debugfs_seq_next() declares 'next' with __free(put_device), which causes put_device() to be called on the returned pointer when the variable goes out of scope. This results in a use-after-free since the seq_file framework receives a pointer whose reference has already been dropped.

Simply removing __free(put_device) would fix the UAF but would leak the reference acquired by bus_find_next_device(), as stop() only calls up_read(&pwrseq_sem) and never releases the device reference.

Continue reading

Fix this by making the reference counting consistent across all seq_file callbacks, matching the standard pattern used by PCI and SCSI:

- start(): use get_device() so it returns a referenced pointer. - next(): explicitly put_device(curr) to release the previous device's reference (no NULL check needed - the seq_file framework only calls next() while the previous return was non-NULL). - stop(): put_device(data) to release the last iterated device's reference, with a NULL guard since stop() may be called with NULL when start() returned NULL or next() reached end-of-sequence.

Scores and how they were measured

CVSS base severity

7.8

Version 3.1As of

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.2%

Scored Percentile 6.4%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-64251 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  4. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  5. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-64251, scored 2026-11-08. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, November 8). Linux kernel: pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next() (CVE-2026-64251). https://kevwire.com/record/CVE-2026-64251

MLA

"Linux kernel: pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next() (CVE-2026-64251)." KEVWire, 8 Nov. 2026, kevwire.com/record/CVE-2026-64251.

Chicago

KEVWire. "Linux kernel: pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next() (CVE-2026-64251)." Last modified November 8, 2026. https://kevwire.com/record/CVE-2026-64251.

Evidence summary (plain text)

Linux kernel: pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next() (Jul 24, 2026).
In the Linux kernel, the following vulnerability has been resolved:

pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next()

pwrseq_debugfs_seq_next() declares 'next' with __free(put_device),
which causes put_device() to be called on the returned pointer when
the variable goes out of scope.  This results in a use-after-free
since the seq_file framework receives a pointer whose reference has
already been dropped.
CVSS 7.8 (version 3.1; evidence as of Nov 8, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-64251).
EPSS 0.2% for the following 30 days, scored Nov 8, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-64251&date=2026-11-08).
Sources:
NVD CVE-2026-64251: https://nvd.nist.gov/vuln/detail/CVE-2026-64251
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-08T20:00:58.436Z&lastModEndDate=2026-11-08T21:40:55.808Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-08T19:30:56.990Z&lastModEndDate=2026-11-08T21:00:56.486Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-08T18:56:00.158Z&lastModEndDate=2026-11-08T20:30:55.736Z&resultsPerPage=500&startIndex=0
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-64251&date=2026-11-08
Record ID: CVE-2026-64251.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Nov 8, 2026, 20:31 UTC. Ingestion is not an independent editorial investigation.

NVD status: Analyzed. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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Record details

Record detail