CVE-2023-52751

HIGHNVD 7.87.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2024-05-21. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 5 sources updated this week

Also known asEUVD-2023-59470 (ENISA EUVD) · GHSA-ffvm-4h72-qwr5 (GitHub Security Advisories)Source: ENISA EUVD

7.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

smb: client: fix use-after-free in smb2_query_info_compound()

The following UAF was triggered when running fstests generic/072 with KASAN enabled against Windows Server 2022 and mount options 'multichannel,max_channels=2,vers=3.1.1,mfsymlinks,noperm'

BUG: KASAN: slab-use-after-free in smb2_query_info_compound+0x423/0x6d0 [cifs] Read of size 8 at addr ffff888014941048 by task xfs_io/27534

CPU: 0 PID: 27534 Comm: xfs_io Not tainted 6.6.0-rc7 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 Call Trace: dump_stack_lvl+0x4a/0x80 print_report+0xcf/0x650 ? srso_alias_return_thunk+0x5/0x7f ? srso_alias_return_thunk+0x5/0x7f ? __phys_addr+0x46/0x90 kasan_report+0xda/0x110 ? smb2_query_info_compound+0x423/0x6d0 [cifs] ? smb2_query_info_compound+0x423/0x6d0 [cifs] smb2_query_info_compound+0x423/0x6d0 [cifs] ? __pfx_smb2_query_info_compound+0x10/0x10 [cifs] ? srso_alias_return_thunk+0x5/0x7f ? __stack_depot_save+0x39/0x480 ? kasan_save_stack+0x33/0x60 ? kasan_set_track+0x25/0x30 ? ____kasan_slab_free+0x126/0x170 smb2_queryfs+0xc2/0x2c0 [cifs] ? __pfx_smb2_queryfs+0x10/0x10 [cifs] ? __pfx___lock_acquire+0x10/0x10 smb311_queryfs+0x210/0x220 [cifs] ? __pfx_smb311_queryfs+0x10/0x10 [cifs] ? srso_alias_return_thunk+0x5/0x7f ? __lock_acquire+0x480/0x26c0 ? lock_release+0x1ed/0x640 ? srso_alias_return_thunk+0x5/0x7f ? do_raw_spin_unlock+0x9b/0x100 cifs_statfs+0x18c/0x4b0 [cifs] statfs_by_dentry+0x9b/0xf0 fd_statfs+0x4e/0xb0 __do_sys_fstatfs+0x7f/0xe0 ? __pfx___do_sys_fstatfs+0x10/0x10 ? srso_alias_return_thunk+0x5/0x7f ? lockdep_hardirqs_on_prepare+0x136/0x200 ? srso_alias_return_thunk+0x5/0x7f do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Allocated by task 27534: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 __kasan_kmalloc+0x8f/0xa0 open_cached_dir+0x71b/0x1240 [cifs] smb2_query_info_compound+0x5c3/0x6d0 [cifs] smb2_queryfs+0xc2/0x2c0 [cifs] smb311_queryfs+0x210/0x220 [cifs] cifs_statfs+0x18c/0x4b0 [cifs] statfs_by_dentry+0x9b/0xf0 fd_statfs+0x4e/0xb0 __do_sys_fstatfs+0x7f/0xe0 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Freed by task 27534: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 kasan_save_free_info+0x2b/0x50 ____kasan_slab_free+0x126/0x170 slab_free_freelist_hook+0xd0/0x1e0 __kmem_cache_free+0x9d/0x1b0 open_cached_dir+0xff5/0x1240 [cifs] smb2_query_info_compound+0x5c3/0x6d0 [cifs] smb2_queryfs+0xc2/0x2c0 [cifs]

This is a race between open_cached_dir() and cached_dir_lease_break() where the cache entry for the open directory handle receives a lease break while creating it. And before returning from open_cached_dir(), we put the last reference of the new @cfid because of !@cfid->has_lease.

Besides the UAF, while running xfstests a lot of missed lease breaks have been noticed in tests that run several concurrent statfs(2) calls on those cached fids

CIFS: VFS: \\w22-root1.gandalf.test No task to wake, unknown frame... CIFS: VFS: \\w22-root1.gandalf.test Cmd: 18 Err: 0x0 Flags: 0x1... CIFS: VFS: \\w22-root1.gandalf.test smb buf 00000000715bfe83 len 108 CIFS: VFS: Dump pending requests: CIFS: VFS: \\w22-root1.gandalf.test No task to wake, unknown frame... CIFS: VFS: \\w22-root1.gandalf.test Cmd: 18 Err: 0x0 Flags: 0x1... CIFS: VFS: \\w22-root1.gandalf.test smb buf 000000005aa7316e len 108 ...

To fix both, in open_cached_dir() ensure that @cfid->has_lease is set right before sending out compounded request so that any potential lease break will be get processed by demultiplex thread while we're still caching @cfid. And, if open failed for some reason, re-check @cfid->has_lease to decide whether or not put lease reference.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
35
EG Risk 35/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity78% × 45%
Impact severity (EG Severity): CVSS 7.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
15th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.

EG Severity
7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-29). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

May 21, 2024

Last Modified

October 30, 2026

Advisory Details (3)

Auto-updated Aug 4, 2026
Patch available.
Web page

smb: client: fix use-after-free in smb2_query_info_compound() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/93877b9afc2994c89362007aac480a7b150f386f
Web page

smb: client: fix use-after-free in smb2_query_info_compound() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6db94d08359c43f2c8fe372811cdee04564a41b9
Web page

smb: client: fix use-after-free in smb2_query_info_compound() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5c86919455c1edec99ebd3338ad213b59271a71b

Vendor Advisories for CVE-2023-52751(3)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(4)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulinux-tools-azure-lts-22.04 (5.15.0.1075.73) @ jammy2026-10-30ubuntu
ubuntulinux-tools-azure-edge (5.15.0.1078.87~20.04.1) @ focal2026-10-30ubuntu
redhatkernel-0:5.14.0-503.11.1.el9_52024-11-12redhat
linuxKernel @ 6.5.13 (fixes >=6.1.0)—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 7.2~rc7-1~exp1 (353 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 6.5.13-1: fixed in 6.5.13-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 6.5.13-1: fixed in 6.5.13-1
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(2)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 16× in last 7d / 47× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 94 of 222 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 6 repeat rows among the latest 100 are merged into the row they repeat. The 128 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:40 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  2. 2026-11-01 16:31 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  3. 2026-10-31 16:30 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  4. 2026-10-30 16:31 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  5. 2026-10-30 13:30 UTCVendor advisory
  6. 2026-10-30 13:30 UTCGHSA enrichmentGHSA-ffvm-4h72-qwr5 · GitHub severity HIGH · GitHub CVSS 7.8
  7. 2026-10-30 12:31 UTCEG score recompute
  8. 2026-10-30 12:31 UTCVendor advisory
  9. 2026-10-30 12:31 UTCGHSA enrichmentGHSA-ffvm-4h72-qwr5 · GitHub severity HIGH · GitHub CVSS 7.8
  10. 2026-10-29 16:30 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  11. 2026-10-28 20:00 UTCEG score recompute
  12. 2026-10-28 20:00 UTCVendor advisory
  13. 2026-10-28 20:00 UTCGHSA enrichmentGHSA-ffvm-4h72-qwr5 · GitHub severity HIGH · GitHub CVSS 7.8
  14. 2026-10-28 18:55 UTCOSV refresh
  15. 2026-10-28 16:29 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  16. 2026-10-27 16:29 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  17. 2026-10-26 16:29 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  18. 2026-10-25 17:28 UTCEG score recompute
  19. 2026-10-25 16:30 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  20. 2026-10-24 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  21. 2026-10-23 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  22. 2026-10-22 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  23. 2026-10-21 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  24. 2026-10-20 21:18 UTCEG score recompute
  25. 2026-10-20 21:18 UTCVendor advisory
Show 69 more
  1. 2026-10-20 21:18 UTCGHSA enrichmentGHSA-ffvm-4h72-qwr5 · GitHub severity HIGH · GitHub CVSS 7.8
  2. 2026-10-20 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  3. 2026-10-19 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  4. 2026-10-19 14:55 UTCOSV refresh
  5. 2026-10-18 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  6. 2026-10-18 07:42 UTCEG score recompute
  7. 2026-10-17 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  8. 2026-10-16 16:36 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  9. 2026-10-15 16:29 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  10. 2026-10-14 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  11. 2026-10-13 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  12. 2026-10-12 18:13 UTCEG score recompute
  13. 2026-10-12 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  14. 2026-10-11 21:38 UTCEG score recompute
  15. 2026-10-11 13:45 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  16. 2026-10-10 19:58 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  17. 2026-10-09 20:05 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  18. 2026-10-08 17:06 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  19. 2026-10-07 23:46 UTCEPSS rescoreEPSS 0.2% · 14th percentile
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  22. 2026-10-04 23:20 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  23. 2026-10-03 14:23 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  24. 2026-10-01 19:48 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  25. 2026-09-30 16:36 UTCEG score recompute
  26. 2026-09-30 15:01 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  27. 2026-09-29 15:17 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  28. 2026-09-28 13:49 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  29. 2026-09-26 21:11 UTCOSV refresh
  30. 2026-09-26 00:22 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  31. 2026-09-24 14:01 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  32. 2026-09-23 13:46 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  33. 2026-09-20 20:14 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  34. 2026-09-18 19:26 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  35. 2026-09-16 14:06 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  36. 2026-09-16 05:11 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  37. 2026-09-15 03:08 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  38. 2026-09-13 16:45 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  39. 2026-09-12 14:58 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  40. 2026-09-11 14:51 UTCEPSS rescoreEPSS 0.2% · 15th percentile
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  42. 2026-09-08 21:58 UTCEPSS rescoreEPSS 0.2% · 15th percentile
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  44. 2026-09-07 06:48 UTCOSV refresh
  45. 2026-09-06 13:46 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  46. 2026-09-05 15:26 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  47. 2026-09-04 13:58 UTCEPSS rescoreEPSS 0.2% · 15th percentile
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  50. 2026-09-01 13:52 UTCEPSS rescoreEPSS 0.2% · 15th percentile
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  52. 2026-08-30 19:15 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  53. 2026-08-30 01:20 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  54. 2026-08-28 21:39 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  55. 2026-08-27 14:23 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  56. 2026-08-26 14:44 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  57. 2026-08-25 13:47 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  58. 2026-08-23 00:17 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  59. 2026-08-21 23:47 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  60. 2026-08-20 22:53 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  61. 2026-08-20 16:31 UTCOSV refresh
  62. 2026-08-19 17:02 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  63. 2026-08-18 13:46 UTCEPSS rescoreEPSS 0.2% · 15th percentile
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Related CVEs(same vendor + same CWE)· as of November 1, 2026

Frequently asked(5)

What is CVE-2023-52751?
CVE-2023-52751 is a high-severity vulnerability; its CVE record was published on May 21, 2024. In the Linux kernel, the following vulnerability has been resolved: smb: client: fix use-after-free in smb2_query_info_compound() The following UAF was triggered when running fstests generic/072 with KASAN enabled against Windows Server 2022 and mount options…
When was the CVE record for CVE-2023-52751 published?
The CVE record for CVE-2023-52751 was published on May 21, 2024. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 30, 2026; the record at its source may have been updated since.
Is CVE-2023-52751 actively exploited?
CVE-2023-52751 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (15th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2023-52751?
CVE-2023-52751 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2023-52751?
A fix for CVE-2023-52751 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2023-52751 are linked in the Vendor Advisories panel on this page.

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