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NVD / CVE Program· CNA Linux

CVE-2025-40233: ocfs2: clear extent cache after moving/defragmenting 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: 0.15% (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 78a63493f8e352296dbc7cb7b3f4973105e8679e, 93166bc53c0e3587058327a4121daea34b4fecd5, 93b1ab422f1966b71561158e1aedce4ec100f357.

Low priority for now. Upgrade to Linux Linux 78a63493f8e352296dbc7cb7b3f4973105e8679e, 93166bc53c0e3587058327a4121daea34b4fecd5, 93b1ab422f1966b71561158e1aedce4ec100f357 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: ocfs2: clear extent cache after moving/defragmenting extents The extent map cache can become stale when extents are moved or defragmented, causing subsequent operations to see outdated extent flags. This triggers a BUG_ON in ocfs2_refcount_cal_cow_clusters(). The problem occurs when: 1. copy_file_range() creates a reflinked extent with OCFS2_EXT_REFCOUNTED 2. ioctl(FITRIM) triggers ocfs2_move_extents() 3. __ocfs2_move_extents_range() reads and caches the extent (flags=0x2) 4. ocfs2_move_extent()/ocfs2_defrag_extent() calls __ocfs2_move_extent() which clears OCFS2_EXT_REFCOUNTED flag on disk (flags=0x0) 5. The extent map cache is not invalidated after the move 6. Later write() operations read stale cached flags (0x2) but disk has updated flags (0x0), causing a mismatch 7. BUG_ON(!(rec->e_flags & OCFS2_EXT_REFCOUNTED)) triggers Fix by clearing the extent map cache after each extent move/defrag operation in __ocfs2_move_extents_range(). This ensures subsequent operations read fresh extent data from disk.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Dec 4, 2025
Updated
Oct 19, 2026
EPSS
0.1% · 4th 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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  • No public exploit code on record
  • A fix has been released

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Follow CVE-2025-40233

When you'll hear from us

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  • 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.

—

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

    • 3.0affected
    • 53069d4e76954e2e63c1b3c501051c6fbcf7298c and later · before 93166bc53c0e3587058327a4121daea34b4fecd5affected · git
    • 53069d4e76954e2e63c1b3c501051c6fbcf7298c and later · before a7ee72286efba1d407c6f15a0528e43593fb7007affected · git
    • 53069d4e76954e2e63c1b3c501051c6fbcf7298c and later · before 93b1ab422f1966b71561158e1aedce4ec100f357affected · git
    • 53069d4e76954e2e63c1b3c501051c6fbcf7298c and later · before e92af7737a94a729225d2a5d180eaaa77fe0bbc1affected · git
    • 53069d4e76954e2e63c1b3c501051c6fbcf7298c and later · before aa6a21409dd6221bb268b56bb410e031c632ff9aaffected · git
    • 53069d4e76954e2e63c1b3c501051c6fbcf7298c and later · before bb69928ed578f881e68d26aaf1a8f6e7faab3b44affected · git
    • 53069d4e76954e2e63c1b3c501051c6fbcf7298c and later · before a21750df2f6169af6e039a3bb4893d6c9564e48daffected · git
    • 53069d4e76954e2e63c1b3c501051c6fbcf7298c and later · before 78a63493f8e352296dbc7cb7b3f4973105e8679eaffected · git
    • before 3.0not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.158-16.1.158-1
Debian:13linuxbefore 6.12.57-16.12.57-1
Debian:14linuxbefore 6.17.6-16.17.6-1

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-2025-40231Dec 4, 2025 · vsock: fix lock inversion in vsock_assign_transport()
    0Monitor
  • ← EarlierCVE-2025-40232Dec 4, 2025 · rv: Fully convert enabled_monitors to use list_head as iterator
    0Monitor
  • Later →CVE-2025-40234Dec 4, 2025 · platform/x86: alienware-wmi-wmax: Fix NULL pointer dereference in sleep handlers
    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 Linux78a63493f8e352296dbc7cb7b3f4973105e8679eVendor (CNA)
Linux Linux93166bc53c0e3587058327a4121daea34b4fecd5Vendor (CNA)
Linux Linux93b1ab422f1966b71561158e1aedce4ec100f357Vendor (CNA)
Linux Linuxa21750df2f6169af6e039a3bb4893d6c9564e48dVendor (CNA)
Linux Linuxa7ee72286efba1d407c6f15a0528e43593fb7007Vendor (CNA)
Linux Linuxaa6a21409dd6221bb268b56bb410e031c632ff9aVendor (CNA)
Linux Linuxbb69928ed578f881e68d26aaf1a8f6e7faab3b44Vendor (CNA)
Linux Linuxe92af7737a94a729225d2a5d180eaaa77fe0bbc1Vendor (CNA)
debian:linux6.1.158-1 · 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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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