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NVD / CVE Program· CNA Linux

CVE-2026-31597: ocfs2: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY

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: 0.12% (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 35c2c05261d6f6d84aaa1355afa201d507943e76, 36539c4d536f851a3b346a6ebb27b51bc3d77a94, 3f5e74b5db9353b01ed50f4de84e75b755f8fbc2; azl3 kernel 6.6.134.1-2 on Azure Linux 3.0 6.6.137.1-1; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes.

Low priority for now. Upgrade to Linux Linux 35c2c05261d6f6d84aaa1355afa201d507943e76, 36539c4d536f851a3b346a6ebb27b51bc3d77a94, 3f5e74b5db9353b01ed50f4de84e75b755f8fbc2; azl3 kernel 6.6.134.1-2 on Azure Linux 3.0 6.6.137.1-1; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes 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: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY filemap_fault() may drop the mmap_lock before returning VM_FAULT_RETRY, as documented in mm/filemap.c: "If our return value has VM_FAULT_RETRY set, it's because the mmap_lock may be dropped before doing I/O or by lock_folio_maybe_drop_mmap()." When this happens, a concurrent munmap() can call remove_vma() and free the vm_area_struct via RCU. The saved 'vma' pointer in ocfs2_fault() then becomes a dangling pointer, and the subsequent trace_ocfs2_fault() call dereferences it -- a use-after-free. Fix this by saving ip_blkno as a plain integer before calling filemap_fault(), and removing vma from the trace event. Since ip_blkno is copied by value before the lock can be dropped, it remains valid regardless of what happens to the vma or inode afterward.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Apr 24, 2026
Updated
Aug 5, 2026
EPSS
0.1% · 2th 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
—
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.

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

  • 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

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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 kernel2.6.39 and later · before 6.6.136
  • linux linux kernel6.7 and later · before 6.12.83
  • linux linux kernel6.13 and later · before 6.18.24
  • linux linux kernel6.19 and later · before 6.19.14
  • linux linux kernel7.0 and later · before 7.0.1

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

    • 2.6.39affected
    • 614a9e849ca6ea24843795251cb30af525d5336b and later · before 36539c4d536f851a3b346a6ebb27b51bc3d77a94affected · git
    • 614a9e849ca6ea24843795251cb30af525d5336b and later · before 35c2c05261d6f6d84aaa1355afa201d507943e76affected · git
    • 614a9e849ca6ea24843795251cb30af525d5336b and later · before 3f5e74b5db9353b01ed50f4de84e75b755f8fbc2affected · git
    • 614a9e849ca6ea24843795251cb30af525d5336b and later · before 6f072daefcab1d84ce37c073645615f63be91006affected · git
    • 614a9e849ca6ea24843795251cb30af525d5336b and later · before 4cf2768a0291a0cdd0dae801ea0eafa3878a349daffected · git
    • 614a9e849ca6ea24843795251cb30af525d5336b and later · before d45ff441b416d4aa1af72b1db23d959601c04da2affected · git
    • 614a9e849ca6ea24843795251cb30af525d5336b and later · before 76a602fdbb78dd05b2da06f74a988cebc97e82d0affected · git
    • 614a9e849ca6ea24843795251cb30af525d5336b and later · before 925bf22c1b823e231b1baea761fe8a1512e442f2affected · git
    • 614a9e849ca6ea24843795251cb30af525d5336b and later · before 7de554cabf160e331e4442e2a9ad874ca9875921affected · git

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.14-16.19.14-1

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-2026-31595Apr 24, 2026 · PCI: endpoint: pci-epf-vntb: Stop cmd_handler work in epf_ntb_epc_cleanup
    22Monitor
  • ← EarlierCVE-2026-31596Apr 24, 2026 · ocfs2: handle invalid dinode in ocfs2_group_extend
    22Monitor
  • Later →CVE-2026-31599Apr 24, 2026 · media: vidtv: fix NULL pointer dereference in vidtv_channel_pmt_match_sections
    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 Linux35c2c05261d6f6d84aaa1355afa201d507943e76Vendor (CNA)
Linux Linux36539c4d536f851a3b346a6ebb27b51bc3d77a94Vendor (CNA)
Linux Linux3f5e74b5db9353b01ed50f4de84e75b755f8fbc2Vendor (CNA)
Linux Linux4cf2768a0291a0cdd0dae801ea0eafa3878a349dVendor (CNA)
Linux Linux6f072daefcab1d84ce37c073645615f63be91006Vendor (CNA)
Linux Linux76a602fdbb78dd05b2da06f74a988cebc97e82d0Vendor (CNA)
Linux Linux7de554cabf160e331e4442e2a9ad874ca9875921Vendor (CNA)
Linux Linux925bf22c1b823e231b1baea761fe8a1512e442f2Vendor (CNA)
Linux Linuxd45ff441b416d4aa1af72b1db23d959601c04da2Vendor (CNA)
azl3 kernel 6.6.134.1-2 on Azure Linux 3.06.6.137.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0Release NotesMicrosoft (MSRC)
debian:linux6.1.176-1 · 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)

CWE-416 · Use After Free

CVSS vector

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

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

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 (8 more)

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

All records