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Response snapshot Oct 31, 2026, 14:16 UTC

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VulnerabilityCVE-2026-99136

Linux kernel: dm-crypt: fix a tiny race condition in crypt_dec_pending

In the Linux kernel, the following vulnerability has been resolved: dm-crypt: fix a tiny race condition in crypt_dec_pending crypt_dec_pending reads io->error before calling atomic_dec_and_test.

At a glance

Exploited
Not known
Severity
7.0 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-2026-99136 (opens a new tab)

What happened

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

dm-crypt: fix a tiny race condition in crypt_dec_pending

crypt_dec_pending reads io->error before calling atomic_dec_and_test. Another context, for example crypt_endio called from an interrupt, may set io->error and drop its reference between the read and the decrement. crypt_dec_pending then drops the last reference and completes the bio with the stale status - so a read that failed and was never decrypted, or a write that failed, is reported as successful.

The read was placed before the decrement by commit b35f8caa0890 ("dm crypt: wait for endio to complete before destruction"), because that commit freed dm_crypt_io before calling bio_endio. This is no longer the case, dm_crypt_io lives in the per-bio data now.

Continue reading

Read io->error after atomic_dec_and_test instead. atomic_dec_and_test is fully ordered, so no additional barrier is needed.

Scores and how they were measured

CVSS base severity

7.0

Version 3.1As of

CVSS:3.1/AV:L/AC:H/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-2026-99136 (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

Cite this record

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

APA

KEVWire. (2026, October 31). Linux kernel: dm-crypt: fix a tiny race condition in crypt_dec_pending (CVE-2026-99136). https://kevwire.com/record/CVE-2026-99136

MLA

"Linux kernel: dm-crypt: fix a tiny race condition in crypt_dec_pending (CVE-2026-99136)." KEVWire, 31 Oct. 2026, kevwire.com/record/CVE-2026-99136.

Chicago

KEVWire. "Linux kernel: dm-crypt: fix a tiny race condition in crypt_dec_pending (CVE-2026-99136)." Last modified October 31, 2026. https://kevwire.com/record/CVE-2026-99136.

Evidence summary (plain text)

Linux kernel: dm-crypt: fix a tiny race condition in crypt_dec_pending (Oct 28, 2026).
In the Linux kernel, the following vulnerability has been resolved:

dm-crypt: fix a tiny race condition in crypt_dec_pending

crypt_dec_pending reads io->error before calling atomic_dec_and_test.
Another context, for example crypt_endio called from an interrupt, may
set io->error and drop its reference between the read and the
decrement. crypt_dec_pending then drops the last reference and completes
the bio with the stale status - so a read that failed and was never
decrypted, or a write that failed, is reported as successful.
CVSS 7.0 (version 3.1; evidence as of Oct 31, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-99136).
Sources:
NVD CVE-2026-99136: https://nvd.nist.gov/vuln/detail/CVE-2026-99136
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-31T12:40:58.114Z&lastModEndDate=2026-10-31T14:15:57.636Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-31T10:50:56.512Z&lastModEndDate=2026-10-31T13:40:56.165Z&resultsPerPage=500&startIndex=0
Record ID: CVE-2026-99136.
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: Oct 31, 2026, 14:15 UTC. Ingestion is not an independent editorial investigation.

NVD status: Received. 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

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