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NVD / CVE Program· CNA Linux

CVE-2023-53692: ext4: fix use-after-free read in ext4_find_extent for bigalloc + inline

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 0ce15000dee0ecd6f235f925a327803e2ef489c6, 11c87c8df2cae1d6be83c07e59fef0792de73482, 14da044725a3ab10affa3566d29c15737c0e67a4.

Low priority for now. Upgrade to Linux Linux 0ce15000dee0ecd6f235f925a327803e2ef489c6, 11c87c8df2cae1d6be83c07e59fef0792de73482, 14da044725a3ab10affa3566d29c15737c0e67a4 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: ext4: fix use-after-free read in ext4_find_extent for bigalloc + inline Syzbot found the following issue: loop0: detected capacity change from 0 to 2048 EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none. ================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch_idx fs/ext4/extents.c:768 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0x76e/0xd90 fs/ext4/extents.c:931 Read of size 4 at addr ffff888073644750 by task syz-executor420/5067 CPU: 0 PID: 5067 Comm: syz-executor420 Not tainted 6.2.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106 print_address_description+0x74/0x340 mm/kasan/report.c:306 print_report+0x107/0x1f0 mm/kasan/report.c:417 kasan_report+0xcd/0x100 mm/kasan/report.c:517 ext4_ext_binsearch_idx fs/ext4/extents.c:768 [inline] ext4_find_extent+0x76e/0xd90 fs/ext4/extents.c:931 ext4_clu_mapped+0x117/0x970 fs/ext4/extents.c:5809 ext4_insert_delayed_block fs/ext4/inode.c:1696 [inline] ext4_da_map_blocks fs/ext4/inode.c:1806 [inline] ext4_da_get_block_prep+0x9e8/0x13c0 fs/ext4/inode.c:1870 ext4_block_write_begin+0x6a8/0x2290 fs/ext4/inode.c:1098 ext4_da_write_begin+0x539/0x760 fs/ext4/inode.c:3082 generic_perform_write+0x2e4/0x5e0 mm/filemap.c:3772 ext4_buffered_write_iter+0x122/0x3a0 fs/ext4/file.c:285 ext4_file_write_iter+0x1d0/0x18f0 call_write_iter include/linux/fs.h:2186 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7dc/0xc50 fs/read_write.c:584 ksys_write+0x177/0x2a0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f4b7a9737b9 RSP: 002b:00007ffc5cac3668 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4b7a9737b9 RDX: 00000000175d9003 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 00007f4b7a933050 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000079f R11: 0000000000000246 R12: 00007f4b7a9330e0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Above issue is happens when enable bigalloc and inline data feature. As commit 131294c35ed6 fixed delayed allocation bug in ext4_clu_mapped for bigalloc + inline. But it only resolved issue when has inline data, if inline data has been converted to extent(ext4_da_convert_inline_data_to_extent) before writepages, there is no EXT4_STATE_MAY_INLINE_DATA flag. However i_data is still store inline data in this scene. Then will trigger UAF when find extent. To resolve above issue, there is need to add judge "ext4_has_inline_data(inode)" in ext4_clu_mapped().

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Oct 22, 2025
Updated
Oct 28, 2026
EPSS
0.1% · 5th percentile
CWE
—

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
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

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

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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.

—

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

    • c0c8edbc8abbe8f16d80a1d794d1ba2c12b6f193, 6.2affected
    • 1ed1eef0551bebee8e56973ccd0900e3578edfb7 and later · before 0ce15000dee0ecd6f235f925a327803e2ef489c6affected · git
    • 6f4200ec76a0d31200c308ec5a71c68df5417004 and later · before a34f6dcb78c654ab905642c1b4e7e5fbb4f0babeaffected · git
    • 9404839e0c9db5a517ea83c0ca3388b39d105fdf and later · before 770b0613637f59f3091dda1ff0c23671a5326b9caffected · git
    • d440d6427a5e3a877c1c259b8d2b216ddb65e185 and later · before 40566def189c513be2c694681256d7486cc6e368affected · git
    • 81b915181c630ee1cffa052e52874fe4e1ba91ac and later · before 96d440bee177669dc0acedca0abd73bae6a9be8baffected · git
    • 131294c35ed6f777bd4e79d42af13b5c41bf2775 and later · before 11c87c8df2cae1d6be83c07e59fef0792de73482affected · git
    • 131294c35ed6f777bd4e79d42af13b5c41bf2775 and later · before 14da044725a3ab10affa3566d29c15737c0e67a4affected · git
    • 131294c35ed6f777bd4e79d42af13b5c41bf2775 and later · before 835659598c67907b98cd2aa57bb951dfaf675c69affected · git
    • 4.19.270 and later · before 4.19.271affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.37-16.1.37-1
Debian:13linuxbefore 6.3.7-16.3.7-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2022-50582Oct 22, 2025 · regulator: core: Prevent integer underflow
    0Monitor
  • ← EarlierCVE-2023-53728Oct 22, 2025 · posix-timers: Ensure timer ID search-loop limit is valid
    0Monitor
  • Later →CVE-2023-53693Oct 22, 2025 · USB: gadget: Fix the memory leak in raw_gadget driver
    0Monitor

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 Linux0ce15000dee0ecd6f235f925a327803e2ef489c6Vendor (CNA)
Linux Linux11c87c8df2cae1d6be83c07e59fef0792de73482Vendor (CNA)
Linux Linux14da044725a3ab10affa3566d29c15737c0e67a4Vendor (CNA)
Linux Linux4.19.271Vendor (CNA)
Linux Linux40566def189c513be2c694681256d7486cc6e368Vendor (CNA)
Linux Linux5.10.180Vendor (CNA)
Linux Linux5.15.111Vendor (CNA)
Linux Linux5.4.243Vendor (CNA)
Linux Linux6.1Vendor (CNA)
Linux Linux6.1.28Vendor (CNA)
Linux Linux770b0613637f59f3091dda1ff0c23671a5326b9cVendor (CNA)
Linux Linux835659598c67907b98cd2aa57bb951dfaf675c69Vendor (CNA)
Linux Linux96d440bee177669dc0acedca0abd73bae6a9be8bVendor (CNA)
Linux Linuxa34f6dcb78c654ab905642c1b4e7e5fbb4f0babeVendor (CNA)
debian:linux6.1.37-1 · 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.
  • 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)

—

CVSS vector

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

nvd-secondary

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

  1. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records