NVD / CVE Program· CNA Linux

CVE-2026-23221: bus: fsl-mc: fix use-after-free in driver_override_show()

Noroxi assessment

Priority: Monitor (action score 31/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.14% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 148891e95014b5dc5878acefa57f1940c281c431, 1d6bd6183e723a7b256ff34bbb5b498b5f4f2ec0, a2ae33e1c6361e960a4d00f7cf75d880b54f9528; azl3 kernel 6.6.126.1-1 on Azure Linux 3.0 6.6.130.1-1; cbl2 kernel 5.15.200.1-1 on CBL Mariner 2.0 5.15.202.1-1.

Low priority for now. Upgrade to Linux Linux 148891e95014b5dc5878acefa57f1940c281c431, 1d6bd6183e723a7b256ff34bbb5b498b5f4f2ec0, a2ae33e1c6361e960a4d00f7cf75d880b54f9528; azl3 kernel 6.6.126.1-1 on Azure Linux 3.0 6.6.130.1-1; cbl2 kernel 5.15.200.1-1 on CBL Mariner 2.0 5.15.202.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: bus: fsl-mc: fix use-after-free in driver_override_show() The driver_override_show() function reads the driver_override string without holding the device_lock. However, driver_override_store() uses driver_set_override(), which modifies and frees the string while holding the device_lock. This can result in a concurrent use-after-free if the string is freed by the store function while being read by the show function. Fix this by holding the device_lock around the read operation.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

Published: Feb 18, 2026
Updated: Jun 17, 2026
EPSS: 0.1% · 3th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

linux linux kernel5.10 and later · before 5.15.201
linux linux kernel5.16 and later · before 6.1.164
linux linux kernel6.2 and later · before 6.6.127
linux linux kernel6.7 and later · before 6.12.74
linux linux kernel6.13 and later · before 6.18.11
linux linux kernel6.19 and later · before 6.19.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 5.10affected
- 1f86a00c1159fd77e66b1bd6ff1a183f4d46f34d and later · before c71dfb7833db7af652ee8f65011f14c97c47405daffected · git
- 1f86a00c1159fd77e66b1bd6ff1a183f4d46f34d and later · before c424e72cfa67e7e1477035058a8a659f2c0ea637affected · git
- 1f86a00c1159fd77e66b1bd6ff1a183f4d46f34d and later · before b1983840287303e0dfb401b1b6cecc5ea7471e90affected · git
- 1f86a00c1159fd77e66b1bd6ff1a183f4d46f34d and later · before dd8ba8c0c3f3916d4ee1e3a09da9cd5caff5d227affected · git
- 1f86a00c1159fd77e66b1bd6ff1a183f4d46f34d and later · before 1d6bd6183e723a7b256ff34bbb5b498b5f4f2ec0affected · git
- 1f86a00c1159fd77e66b1bd6ff1a183f4d46f34d and later · before a2ae33e1c6361e960a4d00f7cf75d880b54f9528affected · git
- 1f86a00c1159fd77e66b1bd6ff1a183f4d46f34d and later · before 148891e95014b5dc5878acefa57f1940c281c431affected · git
- before 5.10not affected · semver
- 5.15.201 and later · up to and including 5.15.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.164-1	6.1.164-1
Debian:13	linux	before 6.12.74-2	6.12.74-2
Debian:14	linux	before 6.18.12-1	6.18.12-1
openSUSE:Tumbleweed	kernel-source	before 6.19.8-1.1	6.19.8-1.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
90Now
CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
89Now
CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
85Now

Published before and after this one in the same product

← EarlierCVE-2025-71237Feb 18, 2026 · nilfs2: Fix potential block overflow that cause system hang
22Monitor
← EarlierCVE-2026-23220Feb 18, 2026 · ksmbd: fix infinite loop caused by next_smb2_rcv_hdr_off reset in error paths
22Monitor
Later →CVE-2026-23222Feb 18, 2026 · crypto: omap - Allocate OMAP_CRYPTO_FORCE_COPY scatterlists correctly
22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	148891e95014b5dc5878acefa57f1940c281c431	Vendor (CNA)
Linux Linux	1d6bd6183e723a7b256ff34bbb5b498b5f4f2ec0	Vendor (CNA)
Linux Linux	a2ae33e1c6361e960a4d00f7cf75d880b54f9528	Vendor (CNA)
Linux Linux	b1983840287303e0dfb401b1b6cecc5ea7471e90	Vendor (CNA)
Linux Linux	c424e72cfa67e7e1477035058a8a659f2c0ea637	Vendor (CNA)
Linux Linux	c71dfb7833db7af652ee8f65011f14c97c47405d	Vendor (CNA)
Linux Linux	dd8ba8c0c3f3916d4ee1e3a09da9cd5caff5d227	Vendor (CNA)
azl3 kernel 6.6.126.1-1 on Azure Linux 3.0	6.6.130.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
cbl2 kernel 5.15.200.1-1 on CBL Mariner 2.0	5.15.202.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.164-1 · Debian:12	Package registry (OSV)
opensuse:kernel-source	6.19.8-1.1 · openSUSE:Tumbleweed	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/148891e95014b5dc5878acefa57f1940c281c431

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records