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NVD / CVE Program· CNA Linux

CVE-2023-52480: ksmbd: fix race condition between session lookup and expire

HighCVSS 7.0 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 28/100)

  • 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: 0.49% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: Linux Linux 18ced78b0ebccc2d16f426143dc56ab3aad666be, 53ff5cf89142b978b1a5ca8dc4d4425e6a09745f, 6.1.57.
  • Severity is disputed: the assigning authority (CNA) scores it 9.8, NVD 7.0.

Low priority for now. Upgrade to Linux Linux 18ced78b0ebccc2d16f426143dc56ab3aad666be, 53ff5cf89142b978b1a5ca8dc4d4425e6a09745f, 6.1.57 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: ksmbd: fix race condition between session lookup and expire Thread A + Thread B ksmbd_session_lookup | smb2_sess_setup sess = xa_load | | | xa_erase(&conn->sessions, sess->id); | | ksmbd_session_destroy(sess) --> kfree(sess) | // UAF! | sess->last_active = jiffies | + This patch add rwsem to fix race condition between ksmbd_session_lookup and ksmbd_expire_session.

Published
Feb 29, 2024
Updated
Aug 15, 2026
EPSS
0.4% · 42th percentile

Report tools

JSON

Action score

28

Monitor

Low priority for now.

CVSS
28 / 40 · 7.0 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.0
CNA · Linux
9.8
2.8 point gap

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

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

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-52480

When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

VendorProduct
linuxlinux kernel

Affected versions

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

  • linux linux kernel5.15 and later · before 5.15.145
  • linux linux kernel5.16 and later · before 6.1.57
  • linux linux kernel6.2 and later · before 6.5.7
  • linux linux kernel6.6

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

    • 6.4, 750a2d772e9d9ff377fd32e3b6797bf2cd847a7a, 6775ee7ef4b37c521aa4cf3730f54554c4875542affected
    • 6.3.2 and later · before 6.4affected · semver
    • a6a9601ba995d0fec635324cb9fd8d14f9bea14e and later · before c77fd3e25a51ac92b0f1b347a96eff6a0b4f066faffected · git
    • 1fc8a2b14ef5223f8e0b95faba2ee0a6e4d0f99d and later · before a2ca5fd3dbcc665e1169044fa0c9e3eba779202baffected · git
    • ea174a91893956450510945a0c5d1a10b5323656 and later · before 18ced78b0ebccc2d16f426143dc56ab3aad666beaffected · git
    • ea174a91893956450510945a0c5d1a10b5323656 and later · before 53ff5cf89142b978b1a5ca8dc4d4425e6a09745faffected · git
    • 6.1.29 and later · before 6.1.57affected · semver
    • 6.2.16 and later · before 6.3affected · semver
    • before 6.4not affected · semver
    • 6.1.57 and later · up to and including 6.1.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.64-16.1.64-1
Debian:13linuxbefore 6.5.8-16.5.8-1

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-2023-52478Feb 29, 2024 · HID: logitech-hidpp: Fix kernel crash on receiver USB disconnect
    18Monitor
  • ← EarlierCVE-2023-52479Feb 29, 2024 · ksmbd: fix uaf in smb20_oplock_break_ack
    35Monitor
  • Later →CVE-2023-52481Feb 29, 2024 · arm64: errata: Add Cortex-A520 speculative unprivileged load workaround
    18Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
Linux Linux18ced78b0ebccc2d16f426143dc56ab3aad666beVendor (CNA)
Linux Linux53ff5cf89142b978b1a5ca8dc4d4425e6a09745fVendor (CNA)
Linux Linux6.1.57Vendor (CNA)
Linux Linux6.3Vendor (CNA)
Linux Linux6.4Vendor (CNA)
Linux Linuxa2ca5fd3dbcc665e1169044fa0c9e3eba779202bVendor (CNA)
Linux Linuxc77fd3e25a51ac92b0f1b347a96eff6a0b4f066fVendor (CNA)
debian:linux6.1.64-1 · Debian:12Package 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.
  • Special conditions such as timing or configuration are required.

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
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSS vector

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

nvd-primary

Attack context

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

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (3 more)

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

All records