NVD / CVE Program· CNA Linux

CVE-2023-53311: nilfs2: fix use-after-free of nilfs_root in dirtying inodes via iput

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: 0.16% (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 11afd67f1b3c28eb216e50a3ca8dbcb69bb71793, 3645510cf926e6af2f4d44899370d7e5331c93bd, 37207240872456fbab44a110bde6640445233963.

Low priority for now. Upgrade to Linux Linux 11afd67f1b3c28eb216e50a3ca8dbcb69bb71793, 3645510cf926e6af2f4d44899370d7e5331c93bd, 37207240872456fbab44a110bde6640445233963 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: nilfs2: fix use-after-free of nilfs_root in dirtying inodes via iput During unmount process of nilfs2, nothing holds nilfs_root structure after nilfs2 detaches its writer in nilfs_detach_log_writer(). Previously, nilfs_evict_inode() could cause use-after-free read for nilfs_root if inodes are left in "garbage_list" and released by nilfs_dispose_list at the end of nilfs_detach_log_writer(), and this bug was fixed by commit 9b5a04ac3ad9 ("nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()"). However, it turned out that there is another possibility of UAF in the call path where mark_inode_dirty_sync() is called from iput(): nilfs_detach_log_writer() nilfs_dispose_list() iput() mark_inode_dirty_sync() __mark_inode_dirty() nilfs_dirty_inode() __nilfs_mark_inode_dirty() nilfs_load_inode_block() --> causes UAF of nilfs_root struct This can happen after commit 0ae45f63d4ef ("vfs: add support for a lazytime mount option"), which changed iput() to call mark_inode_dirty_sync() on its final reference if i_state has I_DIRTY_TIME flag and i_nlink is non-zero. This issue appears after commit 28a65b49eb53 ("nilfs2: do not write dirty data after degenerating to read-only") when using the syzbot reproducer, but the issue has potentially existed before. Fix this issue by adding a "purging flag" to the nilfs structure, setting that flag while disposing the "garbage_list" and checking it in __nilfs_mark_inode_dirty(). Unlike commit 9b5a04ac3ad9 ("nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()"), this patch does not rely on ns_writer to determine whether to skip operations, so as not to break recovery on mount. The nilfs_salvage_orphan_logs routine dirties the buffer of salvaged data before attaching the log writer, so changing __nilfs_mark_inode_dirty() to skip the operation when ns_writer is NULL will cause recovery write to fail. The purpose of using the cleanup-only flag is to allow for narrowing of such conditions.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

BDU:2026-03324

Published: Sep 16, 2025
Updated: Aug 5, 2026
EPSS: 0.1% · 5th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

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

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 7.8
CNA · Linux: 7.8; agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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 kernel4.0 and later · before 4.14.323
linux linux kernel4.15 and later · before 4.19.292
linux linux kernel4.20 and later · before 5.4.254
linux linux kernel5.5 and later · before 5.10.191
linux linux kernel5.11 and later · before 5.15.127
linux linux kernel5.16 and later · before 6.1.46
linux linux kernel6.2 and later · before 6.4.11
linux linux kernel6.5

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
- 4.0affected
- 0ae45f63d4ef8d8eeec49c7d8b44a1775fff13e8 and later · before 11afd67f1b3c28eb216e50a3ca8dbcb69bb71793affected · git
- 0ae45f63d4ef8d8eeec49c7d8b44a1775fff13e8 and later · before a3c3b4cbf9b8554120fb230e6516e980c6277487affected · git
- 0ae45f63d4ef8d8eeec49c7d8b44a1775fff13e8 and later · before d2c539c216cce74837a9cf5804eb205939b82227affected · git
- 0ae45f63d4ef8d8eeec49c7d8b44a1775fff13e8 and later · before 37207240872456fbab44a110bde6640445233963affected · git
- 0ae45f63d4ef8d8eeec49c7d8b44a1775fff13e8 and later · before 3645510cf926e6af2f4d44899370d7e5331c93bdaffected · git
- 0ae45f63d4ef8d8eeec49c7d8b44a1775fff13e8 and later · before 7532ff6edbf5242376b24a95a2fefb59bb653e5aaffected · git
- 0ae45f63d4ef8d8eeec49c7d8b44a1775fff13e8 and later · before 5828d5f5dc877dcfdd7b23102e978e2ecfd86d82affected · git
- 0ae45f63d4ef8d8eeec49c7d8b44a1775fff13e8 and later · before f8654743a0e6909dc634cbfad6db6816f10f3399affected · git
- before 4.0not 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 6.1.52-1	6.1.52-1
Debian:13	linux	before 6.4.11-1	6.4.11-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

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CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
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Published before and after this one in the same product

← EarlierCVE-2023-53309Sep 16, 2025 · drm/radeon: Fix integer overflow in radeon_cs_parser_init
22Monitor
← EarlierCVE-2023-53310Sep 16, 2025 · power: supply: axp288_fuel_gauge: Fix external_power_changed race
18Monitor
Later →CVE-2023-53312Sep 16, 2025 · net: fix net_dev_start_xmit trace event vs skb_transport_offset()
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	11afd67f1b3c28eb216e50a3ca8dbcb69bb71793	Vendor (CNA)
Linux Linux	3645510cf926e6af2f4d44899370d7e5331c93bd	Vendor (CNA)
Linux Linux	37207240872456fbab44a110bde6640445233963	Vendor (CNA)
Linux Linux	5828d5f5dc877dcfdd7b23102e978e2ecfd86d82	Vendor (CNA)
Linux Linux	7532ff6edbf5242376b24a95a2fefb59bb653e5a	Vendor (CNA)
Linux Linux	a3c3b4cbf9b8554120fb230e6516e980c6277487	Vendor (CNA)
Linux Linux	d2c539c216cce74837a9cf5804eb205939b82227	Vendor (CNA)
Linux Linux	f8654743a0e6909dc634cbfad6db6816f10f3399	Vendor (CNA)
debian:linux	6.1.52-1 · Debian:12	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, 10:10 PM UTC

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

References

git.kernel.org/stable/c/11afd67f1b3c28eb216e50a3ca8dbcb69bb71793

Show all references (7 more)

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

All records