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Response snapshot Nov 3, 2026, 21:16 UTC

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VulnerabilityCVE-2026-64502

Linux kernel: iio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices

In the Linux kernel, the following vulnerability has been resolved: iio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices ad_sigma_delta_clear_pending_event() falls through to the status register read path for devices with has_registers = false and no rdy_gpiod.

At a glance

Exploited
Not known
Severity
7.8 High (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-64502 (opens a new tab)

What happened

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

iio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices

ad_sigma_delta_clear_pending_event() falls through to the status register read path for devices with has_registers = false and no rdy_gpiod. For such devices, ad_sd_read_reg() skips the address byte entirely and clocks raw MISO bytes with no address phase — making it byte-for-byte identical to reading conversion data.

If a pending conversion result is present, this partially consumes it and corrupts the data stream for the subsequent ad_sd_read_reg() call in ad_sigma_delta_single_conversion().

Continue reading

Furthermore, with num_resetclks = 0 on these devices, data_read_len evaluates to 0. If the clocked byte has bit 7 clear, pending_event is set and the code attempts memset(data + 2, 0xff, 0 - 1), overflowing to SIZE_MAX and corrupting the heap.

Fix by returning 0 immediately when neither rdy_gpiod nor has_registers is set. This is safe for all current registerless devices: ad7191 and ad7780 (with powerdown GPIO) are reset between conversions by CS deassertion, so there is no stale result to drain; ad7780 (without powerdown GPIO) and max11205 are continuously-converting and cycle ~DRDY at the output data rate regardless of whether the previous result was read, so the next falling edge fires naturally.

A future registerless device that holds ~DRDY asserted until data is read would be broken by this early return and would require either num_resetclks set or a rdy-gpio.

The same heap corruption is reachable on any device with rdy_gpiod set but num_resetclks = 0: if the GPIO indicates a pending event, the drain path executes memset(data + 2, 0xff, 0 - 1) regardless of has_registers. Add an explicit data_read_len == 0 guard after the pending event check; the stale result is then consumed by the first ad_sd_read_reg() call in ad_sigma_delta_single_conversion().

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

Not available

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-2026-64502 (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

Cite this record

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

APA

KEVWire. (2026, November 3). Linux kernel: iio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices (CVE-2026-64502). https://kevwire.com/record/CVE-2026-64502

MLA

"Linux kernel: iio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices (CVE-2026-64502)." KEVWire, 3 Nov. 2026, kevwire.com/record/CVE-2026-64502.

Chicago

KEVWire. "Linux kernel: iio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices (CVE-2026-64502)." Last modified November 3, 2026. https://kevwire.com/record/CVE-2026-64502.

Evidence summary (plain text)

Linux kernel: iio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices (Jul 25, 2026).
In the Linux kernel, the following vulnerability has been resolved:

iio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices

ad_sigma_delta_clear_pending_event() falls through to the status register
read path for devices with has_registers = false and no rdy_gpiod. For
such devices, ad_sd_read_reg() skips the address byte entirely and clocks
raw MISO bytes with no address phase — making it byte-for-byte identical
to reading conversion data.
CVSS 7.8 (version 3.1; evidence as of Nov 3, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-64502).
Sources:
NVD CVE-2026-64502: https://nvd.nist.gov/vuln/detail/CVE-2026-64502
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-03T18:06:04.789Z&lastModEndDate=2026-11-03T19:40:57.574Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-03T17:35:57.416Z&lastModEndDate=2026-11-03T19:05:57.748Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-03T17:01:00.112Z&lastModEndDate=2026-11-03T18:35:55.788Z&resultsPerPage=500&startIndex=0
Record ID: CVE-2026-64502.
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 3, 2026, 19:40 UTC. Ingestion is not an independent editorial investigation.

NVD status: Awaiting Analysis. 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.

Record JSON

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Record details

Record detail