Unknown

CVE-2026-98923 — arm64: io: Reject non-user protection in ioremap_prot()

In the Linux kernel, the following vulnerability has been resolved: arm64: io: Reject non-user protection in ioremap_prot() Mapping a stack-top page via /dev/mem with PROT_NONE and then reading that process's /proc/<pid>/cmdline triggers a spurious WARN in ioremap_prot() through generic_access_phys(): WARNING: ./arch/arm64/include/asm/io.h:275 at generic_access_phys Call trace: generic_access_phys+0x1c8/0x228 (P) __access_remote_vm+0x2b4/0x398 access_remote_vm+0x14/0x30 get_mm_cmdline+0xf8/0x2a0 proc_pid_cmdline_read+0x68/0x120 generic_access_phys() passes the protection derived from the user PTE to ioremap_prot(). On arm64, a PROT_NONE mapping is represented by a present-invalid PTE, so pte_present() still returns true and the protection reaches ioremap_prot(). A PROT_NONE mapping does not have PTE_USER, causing the existing WARN_ON_ONCE() in ioremap_prot() to fire even though this is a valid user mapping. Execute-only mappings have the same issue and must not be readable through this path either. ioremap_prot() should therefore reject protection values without PTE_USER without warning. This makes the access fail cleanly for PROT_NONE and execute-only mappings while retaining the existing user-protection contract.

Published Oct 23, 2026 · Updated Oct 23, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.17%

ahead of 6% of scored CVEs · Oct 30, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 64858b76ec67c5fc40fef8ec1841fecb78c1ebde and < fddc90d4af4550af410f52d11bbf6b5f36443838≥ eeecafce5afffb4da703666ebefbd4d6e2a5abf6 and < 0b04af3d88bb7fc69b2d92457890608860e42365≥ 3d64dcc0799c2d6921ba027716b7be721eb19fa8 and < b17aa4955e3a694c663ebe99626e4c76ca4f7cfb≥ 8f098037139b294050053123ab2bc0f819d08932 and < 9b583795feb51f8d50203228d001760d1344ef01≥ 8f098037139b294050053123ab2bc0f819d08932 and < bb756b11ad63832ebee58caf9e8f9381eaecff9fversion d1ad8fe7f72d73e1617bac79f2ec7a3bedf47e2a≥ 6.6.143 and < 6.6.158≥ 6.12.93 and < 6.12.112 and 3 more ≥ 6.18.17 and < 6.18.55≥ 6.19.7 and < 6.20version 7.0	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 24, 2026 → Oct 30, 2026 · 7 reading(s) · max 0.21%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 23, 2026
Affected products added · linux/linux
Oct 23, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Received
Oct 23, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 23, 2026 · Alertas do Telegram
CVE published
Oct 23, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× References added · Oct 23, 2026 – Oct 23, 2026
1× Official description updated · Oct 23, 2026 – Oct 23, 2026

References

5 on the record

git.kernel.org/stable/c/b17aa4955e3a694c663ebe99626e4c76ca4f7cfb
NIST National Vulnerability Database
git.kernel.org/stable/c/0b04af3d88bb7fc69b2d92457890608860e42365
NIST National Vulnerability Database
git.kernel.org/stable/c/fddc90d4af4550af410f52d11bbf6b5f36443838
NIST National Vulnerability Database
git.kernel.org/stable/c/9b583795feb51f8d50203228d001760d1344ef01
NIST National Vulnerability Database
git.kernel.org/stable/c/bb756b11ad63832ebee58caf9e8f9381eaecff9f
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 3d
Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 3d
Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 3d
Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 3d
Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 3d
Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 3d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-98923 is "arm64: io: Reject non-user protection in ioremap_prot()", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.17% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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