CVE-2026-90274

Memory corruption via sequence-count underflow

Published Sep 17, 2026 · Updated Sep 17, 2026

Integer underflow in Linux CoreSight ETM4x allows local users to corrupt kernel memory via trace configuration on affected ARM systems. The reset_store function uses nrseqstate minus one as a loop bound, writing past the sequence-control array when hardware reports zero sequencer states. Exposure requires the affected driver, that hardware condition, and privileged trace configuration access; a specific crash outcome is not documented.

CVSS severity4.2
Medium
EPSS probability0.17%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer underflow in Linux CoreSight ETM4x allows local users to corrupt kernel memory via trace configuration on affected ARM systems. The reset_store function uses nrseqstate minus one as a loop bound, writing past the sequence-control array when hardware reports zero sequencer states. Exposure requires the affected driver, that hardware condition, and privileged trace configuration access; a specific crash outcome is not documented.

The record

CVE
CVE-2026-90274
Published
Sep 17, 2026
Updated
Sep 17, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=2e1cdfe184b5202d51e0611d7a051e2bea303946 <1674d9bff8073bdee5dbc200f56fc3caa28d0566
  2. Affected versionversion=2e1cdfe184b5202d51e0611d7a051e2bea303946 <1ade9a335c69fc735cb7b3f222ed35ab135540fb
  3. Affected versionversion=2e1cdfe184b5202d51e0611d7a051e2bea303946 <4091f2d5b26d117c992ffcce1a5df425a0daedcd
  4. Affected versionversion=2e1cdfe184b5202d51e0611d7a051e2bea303946 <4f9a0f548413bf864f609c9f4bc56e3f1b3577d4
  5. Affected versionversion=2e1cdfe184b5202d51e0611d7a051e2bea303946 <5ac900f73ce1d4d8308f40752b51bc8a02b244d2
  6. Affected versionversion=2e1cdfe184b5202d51e0611d7a051e2bea303946 <8d669db59f7283b838e029af29da12e505265fae
  7. Affected versionversion=2e1cdfe184b5202d51e0611d7a051e2bea303946 <be7b2de5b9a96ae68ffa3528e0a40d63e0fd8148
  8. Affected versionversion=4.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=2e1cdfe184b5202d51e0611d7a051e2bea303946 <1674d9bff8073bdee5dbc200f56fc3caa28d0566; version=2e1cdfe184b5202d51e0611d7a051e2bea303946 <1ade9a335c69fc735cb7b3f222ed35ab135540fb; version=2e1cdfe184b5202d51e0611d7a051e2bea303946 <4091f2d5b26d117c992ffcce1a5df425a0daedcd; version=2e1cdfe184b5202d51e0611d7a051e2bea303946 <4f9a0f548413bf864f609c9f4bc56e3f1b3577d4; version=2e1cdfe184b5202d51e0611d7a051e2bea303946 <5ac900f73ce1d4d8308f40752b51bc8a02b244d2; version=2e1cdfe184b5202d51e0611d7a051e2bea303946 <8d669db59f7283b838e029af29da12e505265fae; version=2e1cdfe184b5202d51e0611d7a051e2bea303946 <be7b2de5b9a96ae68ffa3528e0a40d63e0fd8148; version=4.2

Published CVSS scores

4.2Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L
4.2SUSECVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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