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NVD / CVE Program· CNA Linux

CVE-2023-53485: fs: jfs: Fix UBSAN: array-index-out-of-bounds in dbAllocDmapLev

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: 0.19% (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 0d9e678a82915633b99603f744e7735d1a673d72, 39f6292d75959e8accac0b3e24090094ba0824e9, 4e302336d5ca1767a06beee7596a72d3bdc8d983.

Low priority for now. Upgrade to Linux Linux 0d9e678a82915633b99603f744e7735d1a673d72, 39f6292d75959e8accac0b3e24090094ba0824e9, 4e302336d5ca1767a06beee7596a72d3bdc8d983 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: fs: jfs: Fix UBSAN: array-index-out-of-bounds in dbAllocDmapLev Syzkaller reported the following issue: UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:1965:6 index -84 is out of range for type 's8[341]' (aka 'signed char[341]') CPU: 1 PID: 4995 Comm: syz-executor146 Not tainted 6.4.0-rc6-syzkaller-00037-gb6dad5178cea #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 ubsan_epilogue lib/ubsan.c:217 [inline] __ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348 dbAllocDmapLev+0x3e5/0x430 fs/jfs/jfs_dmap.c:1965 dbAllocCtl+0x113/0x920 fs/jfs/jfs_dmap.c:1809 dbAllocAG+0x28f/0x10b0 fs/jfs/jfs_dmap.c:1350 dbAlloc+0x658/0xca0 fs/jfs/jfs_dmap.c:874 dtSplitUp fs/jfs/jfs_dtree.c:974 [inline] dtInsert+0xda7/0x6b00 fs/jfs/jfs_dtree.c:863 jfs_create+0x7b6/0xbb0 fs/jfs/namei.c:137 lookup_open fs/namei.c:3492 [inline] open_last_lookups fs/namei.c:3560 [inline] path_openat+0x13df/0x3170 fs/namei.c:3788 do_filp_open+0x234/0x490 fs/namei.c:3818 do_sys_openat2+0x13f/0x500 fs/open.c:1356 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x247/0x290 fs/open.c:1383 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f1f4e33f7e9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc21129578 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1f4e33f7e9 RDX: 000000000000275a RSI: 0000000020000040 RDI: 00000000ffffff9c RBP: 00007f1f4e2ff080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1f4e2ff110 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> The bug occurs when the dbAllocDmapLev()function attempts to access dp->tree.stree[leafidx + LEAFIND] while the leafidx value is negative. To rectify this, the patch introduces a safeguard within the dbAllocDmapLev() function. A check has been added to verify if leafidx is negative. If it is, the function immediately returns an I/O error, preventing any further execution that could potentially cause harm. Tested via syzbot.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Oct 1, 2025
Updated
Aug 5, 2026
EPSS
0.1% · 8th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

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

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

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

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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 kernel2.6.12.1 and later · before 4.14.324
  • linux linux kernel4.15 and later · before 4.19.293
  • linux linux kernel4.20 and later · before 5.4.255
  • linux linux kernel5.5 and later · before 5.10.192
  • linux linux kernel5.11 and later · before 5.15.123
  • linux linux kernel5.16 and later · before 6.1.42
  • linux linux kernel6.2 and later · before 6.4.7
  • linux linux kernel2.6.12

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

    • 2.6.12affected
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 0d9e678a82915633b99603f744e7735d1a673d72affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 53b0a362aca2583729e8ca2936ca657ff3247d88affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 6e7d9d76e5654bcdd3cdb7c9441a8113428ecebbaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 911b48eec45152822bccf45cd3563b48256b1520affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 39f6292d75959e8accac0b3e24090094ba0824e9affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before bdf07ab1595b613b03f32dbb5cb379edfa1a7334affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before f2af019091f904ca08b3572ab0111238ad6d17b3affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 4e302336d5ca1767a06beee7596a72d3bdc8d983affected · git
    • before 2.6.12not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.52-16.1.52-1
Debian:13linuxbefore 6.4.11-16.4.11-1

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-2023-53482Oct 1, 2025 · iommu: Fix error unwind in iommu_group_alloc()
    22Monitor
  • ← EarlierCVE-2023-53483Oct 1, 2025 · ACPI: processor: Check for null return of devm_kzalloc() in fch_misc_setup()
    22Monitor
  • Later →CVE-2023-53486Oct 1, 2025 · fs/ntfs3: Enhance the attribute size check
    28Monitor

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 Linux0d9e678a82915633b99603f744e7735d1a673d72Vendor (CNA)
Linux Linux39f6292d75959e8accac0b3e24090094ba0824e9Vendor (CNA)
Linux Linux4e302336d5ca1767a06beee7596a72d3bdc8d983Vendor (CNA)
Linux Linux53b0a362aca2583729e8ca2936ca657ff3247d88Vendor (CNA)
Linux Linux6e7d9d76e5654bcdd3cdb7c9441a8113428ecebbVendor (CNA)
Linux Linux911b48eec45152822bccf45cd3563b48256b1520Vendor (CNA)
Linux Linuxbdf07ab1595b613b03f32dbb5cb379edfa1a7334Vendor (CNA)
Linux Linuxf2af019091f904ca08b3572ab0111238ad6d17b3Vendor (CNA)
debian:linux6.1.52-1 · 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.

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.

  • CVE-2021-47548495 days apartethernet: hisilicon: hns: hns_dsaf_misc: fix a possible array overflow in hns_dsaf_ge_srst_by_port()
    39Monitor
  • CVE-2026-64018291 days apartnet: mana: validate rx_req_idx to prevent out-of-bounds array access
    37Monitor
  • CVE-2026-23246168 days apartwifi: mac80211: bounds-check link_id in ieee80211_ml_reconfiguration
    35Monitor
  • CVE-2026-43110217 days apartwifi: brcmfmac: validate bsscfg indices in IF events
    35Monitor
  • CVE-2026-43172217 days apartwifi: iwlwifi: fix 22000 series SMEM parsing
    35Monitor
  • CVE-2023-5339513 days apartACPICA: Add AML_NO_OPERAND_RESOLVE flag to Timer
    31Monitor

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

CVSS vector

CVSS:3.1/AV:L/AC:L/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

All records