NVD / CVE Program· CNA Linux

CVE-2023-53427: cifs: Fix warning and UAF when destroy the MR list

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: 0.15% (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 275a3d2b9408fc4895e342f772cab9a89960546e, 2d0c4f5f618f58eba03385363717703bee873c64, 3524d6da0fe88aee79f06be6572955d16ad76b39.

Low priority for now. Upgrade to Linux Linux 275a3d2b9408fc4895e342f772cab9a89960546e, 2d0c4f5f618f58eba03385363717703bee873c64, 3524d6da0fe88aee79f06be6572955d16ad76b39 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: cifs: Fix warning and UAF when destroy the MR list If the MR allocate failed, the MR recovery work not initialized and list not cleared. Then will be warning and UAF when release the MR: WARNING: CPU: 4 PID: 824 at kernel/workqueue.c:3066 __flush_work.isra.0+0xf7/0x110 CPU: 4 PID: 824 Comm: mount.cifs Not tainted 6.1.0-rc5+ #82 RIP: 0010:__flush_work.isra.0+0xf7/0x110 Call Trace: <TASK> __cancel_work_timer+0x2ba/0x2e0 smbd_destroy+0x4e1/0x990 _smbd_get_connection+0x1cbd/0x2110 smbd_get_connection+0x21/0x40 cifs_get_tcp_session+0x8ef/0xda0 mount_get_conns+0x60/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 BUG: KASAN: use-after-free in smbd_destroy+0x4fc/0x990 Read of size 8 at addr ffff88810b156a08 by task mount.cifs/824 CPU: 4 PID: 824 Comm: mount.cifs Tainted: G W 6.1.0-rc5+ #82 Call Trace: dump_stack_lvl+0x34/0x44 print_report+0x171/0x472 kasan_report+0xad/0x130 smbd_destroy+0x4fc/0x990 _smbd_get_connection+0x1cbd/0x2110 smbd_get_connection+0x21/0x40 cifs_get_tcp_session+0x8ef/0xda0 mount_get_conns+0x60/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Allocated by task 824: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0x7a/0x90 _smbd_get_connection+0x1b6f/0x2110 smbd_get_connection+0x21/0x40 cifs_get_tcp_session+0x8ef/0xda0 mount_get_conns+0x60/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Freed by task 824: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x40 ____kasan_slab_free+0x143/0x1b0 __kmem_cache_free+0xc8/0x330 _smbd_get_connection+0x1c6a/0x2110 smbd_get_connection+0x21/0x40 cifs_get_tcp_session+0x8ef/0xda0 mount_get_conns+0x60/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Let's initialize the MR recovery work before MR allocate to prevent the warning, remove the MRs from the list to prevent the UAF.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

BDU:2026-03341

Published: Sep 18, 2025
Updated: Jun 17, 2026
EPSS: 0.1% · 4th 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.

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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 kernel4.16 and later · before 4.19.276
linux linux kernel4.20 and later · before 5.4.235
linux linux kernel5.5 and later · before 5.10.173
linux linux kernel5.11 and later · before 5.15.99
linux linux kernel5.16 and later · before 6.1.16
linux linux kernel6.2 and later · before 6.2.3

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
- 4.16affected
- c7398583340a6d82b8bb7f7f21edcde27dc6a898 and later · before 275a3d2b9408fc4895e342f772cab9a89960546eaffected · git
- c7398583340a6d82b8bb7f7f21edcde27dc6a898 and later · before 3524d6da0fe88aee79f06be6572955d16ad76b39affected · git
- c7398583340a6d82b8bb7f7f21edcde27dc6a898 and later · before cfd85a0922c4696d768965e686ad805a58d9d834affected · git
- c7398583340a6d82b8bb7f7f21edcde27dc6a898 and later · before 7cbd5bdb5bd4404a5da4309521134b42c65846c0affected · git
- c7398583340a6d82b8bb7f7f21edcde27dc6a898 and later · before 41832c62a75dad530dc5a2856c92ae5459d497e5affected · git
- c7398583340a6d82b8bb7f7f21edcde27dc6a898 and later · before 2d0c4f5f618f58eba03385363717703bee873c64affected · git
- c7398583340a6d82b8bb7f7f21edcde27dc6a898 and later · before 3e161c2791f8e661eed24a2c624087084d910215affected · git
- before 4.16not affected · semver
- 4.19.276 and later · up to and including 4.19.*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 6.1.20-1	6.1.20-1

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-2023-53425Sep 18, 2025 · media: platform: mediatek: vpu: fix NULL ptr dereference
22Monitor
← EarlierCVE-2023-53426Sep 18, 2025 · xsk: Fix xsk_diag use-after-free error during socket cleanup
31Monitor
Later →CVE-2023-53428Sep 18, 2025 · powercap: arm_scmi: Remove recursion while parsing zones
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	275a3d2b9408fc4895e342f772cab9a89960546e	Vendor (CNA)
Linux Linux	2d0c4f5f618f58eba03385363717703bee873c64	Vendor (CNA)
Linux Linux	3524d6da0fe88aee79f06be6572955d16ad76b39	Vendor (CNA)
Linux Linux	3e161c2791f8e661eed24a2c624087084d910215	Vendor (CNA)
Linux Linux	41832c62a75dad530dc5a2856c92ae5459d497e5	Vendor (CNA)
Linux Linux	7cbd5bdb5bd4404a5da4309521134b42c65846c0	Vendor (CNA)
Linux Linux	cfd85a0922c4696d768965e686ad805a58d9d834	Vendor (CNA)
debian:linux	6.1.20-1 · 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/275a3d2b9408fc4895e342f772cab9a89960546e

Show all references (6 more)

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

All records