CVE-2026-90347

Seccomp bypass via stale syscall argument

Published Sep 17, 2026 · Updated Sep 18, 2026

Seccomp bypass in arm64 Linux 4.8 through 7.2.5 allows local users with ptrace access to alter a syscall argument after filtering. A tracer stopped at SECCOMP_RET_TRACE can rewrite x0 while stale orig_x0 is used when the seccomp filter is re-evaluated. The flaw requires local ptrace access to a traced process on arm64 and permits that process to execute a system call with an unchecked first argument.

CVSS severity8.4
High
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

Seccomp bypass in arm64 Linux 4.8 through 7.2.5 allows local users with ptrace access to alter a syscall argument after filtering. A tracer stopped at SECCOMP_RET_TRACE can rewrite x0 while stale orig_x0 is used when the seccomp filter is re-evaluated. The flaw requires local ptrace access to a traced process on arm64 and permits that process to execute a system call with an unchecked first argument.

The record

CVE
CVE-2026-90347
Published
Sep 17, 2026
Updated
Sep 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1562.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 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=4.8
  2. Affected versionversion=a5cd110cb8369d6b37ef5ccfe56b3fa1338c9615 <88b839ce497ccb1ff92f7ae742c78dd2937ba572
  3. Affected versionversion=a5cd110cb8369d6b37ef5ccfe56b3fa1338c9615 <f433869f23841a50455c4087d85540d5b4d37cde

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.8; version=a5cd110cb8369d6b37ef5ccfe56b3fa1338c9615 <88b839ce497ccb1ff92f7ae742c78dd2937ba572; version=a5cd110cb8369d6b37ef5ccfe56b3fa1338c9615 <f433869f23841a50455c4087d85540d5b4d37cde

Published CVSS scores

8.4National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
3.3Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1562.001Impair Defenses: Disable or Modify Tools

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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