Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2023-53506: udf: Do not bother merging very long extents

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 3d20e3b768aff32112bdce8d3219d923ae75f9f1, 53cafe1d6d8ef9f93318e5bfccc0d24f27d41ced, 5d029799d381a9ee06209a222cae75f04c5d5304.

Low priority for now. Upgrade to Linux Linux 3d20e3b768aff32112bdce8d3219d923ae75f9f1, 53cafe1d6d8ef9f93318e5bfccc0d24f27d41ced, 5d029799d381a9ee06209a222cae75f04c5d5304 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: udf: Do not bother merging very long extents When merging very long extents we try to push as much length as possible to the first extent. However this is unnecessarily complicated and not really worth the trouble. Furthermore there was a bug in the logic resulting in corrupting extents in the file as syzbot reproducer shows. So just don't bother with the merging of extents that are too long together.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Oct 1, 2025
Updated
Oct 15, 2026
EPSS
0.1% · 6th 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%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

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.

Follow CVE-2023-53506

When you'll hear from us

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

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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.

We use this product, ask for help

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 4.14.308
  • linux linux kernel4.15 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
  • 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 d52252a1de4cf96a34f722b0cd8902d8ff78eb57affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 5d029799d381a9ee06209a222cae75f04c5d5304affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 3d20e3b768aff32112bdce8d3219d923ae75f9f1affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 965982feb333aefa9256c0fe188b5f1b958aef63affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 9a8d602f0723586e668bae7e65c832ceb9bcc8bcaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before adac9ac6d2e04ea0782b91a00ba10706002f3ec4affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 7a965da79f2d22601f329cbfce588386b0847544affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 53cafe1d6d8ef9f93318e5bfccc0d24f27d41cedaffected · 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 6.1.20-16.1.20-1

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-2023-53503Oct 1, 2025 · ext4: allow ext4_get_group_info() to fail
    22Monitor
  • ← EarlierCVE-2023-53504Oct 1, 2025 · RDMA/bnxt_re: Properly order ib_device_unalloc() to avoid UAF
    31Monitor
  • Later →CVE-2023-53509Oct 1, 2025 · qed: allow sleep in qed_mcp_trace_dump()
    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 / packageFixed versionSource
Linux Linux3d20e3b768aff32112bdce8d3219d923ae75f9f1Vendor (CNA)
Linux Linux53cafe1d6d8ef9f93318e5bfccc0d24f27d41cedVendor (CNA)
Linux Linux5d029799d381a9ee06209a222cae75f04c5d5304Vendor (CNA)
Linux Linux7a965da79f2d22601f329cbfce588386b0847544Vendor (CNA)
Linux Linux965982feb333aefa9256c0fe188b5f1b958aef63Vendor (CNA)
Linux Linux9a8d602f0723586e668bae7e65c832ceb9bcc8bcVendor (CNA)
Linux Linuxadac9ac6d2e04ea0782b91a00ba10706002f3ec4Vendor (CNA)
Linux Linuxd52252a1de4cf96a34f722b0cd8902d8ff78eb57Vendor (CNA)
debian:linux6.1.20-1 · 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-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.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. 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