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NVD / CVE Program· CNA Linux

CVE-2026-23168: flex_proportions: make fprop_new_period() hardirq safe

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.13% (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 0acc9ba7a1b5ba4d998c5753e709be904e179b75, 78ede9ebd679dadf480dce6f7b798e3603f88348, 884b2590ffcc7222cbbd6298051f4c243cc36f5d.

Low priority for now. Upgrade to Linux Linux 0acc9ba7a1b5ba4d998c5753e709be904e179b75, 78ede9ebd679dadf480dce6f7b798e3603f88348, 884b2590ffcc7222cbbd6298051f4c243cc36f5d 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: flex_proportions: make fprop_new_period() hardirq safe Bernd has reported a lockdep splat from flexible proportions code that is essentially complaining about the following race: <timer fires> run_timer_softirq - we are in softirq context call_timer_fn writeout_period fprop_new_period write_seqcount_begin(&p->sequence); <hardirq is raised> ... blk_mq_end_request() blk_update_request() ext4_end_bio() folio_end_writeback() __wb_writeout_add() __fprop_add_percpu_max() if (unlikely(max_frac < FPROP_FRAC_BASE)) { fprop_fraction_percpu() seq = read_seqcount_begin(&p->sequence); - sees odd sequence so loops indefinitely Note that a deadlock like this is only possible if the bdi has configured maximum fraction of writeout throughput which is very rare in general but frequent for example for FUSE bdis. To fix this problem we have to make sure write section of the sequence counter is irqsafe.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Feb 14, 2026
Updated
Jun 17, 2026
EPSS
0.1% · 2th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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  • No public exploit code on record
  • A fix has been released

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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 kernel6.0 and later · before 6.1.162
  • linux linux kernel6.2 and later · before 6.6.123
  • linux linux kernel6.7 and later · before 6.12.69
  • linux linux kernel6.13 and later · before 6.18.9
  • linux linux kernel6.19

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

    • 6.0affected
    • a91befde350375b1ff954635acdde14dc92cd9a8 and later · before 0acc9ba7a1b5ba4d998c5753e709be904e179b75affected · git
    • a91befde350375b1ff954635acdde14dc92cd9a8 and later · before 884b2590ffcc7222cbbd6298051f4c243cc36f5daffected · git
    • a91befde350375b1ff954635acdde14dc92cd9a8 and later · before 78ede9ebd679dadf480dce6f7b798e3603f88348affected · git
    • a91befde350375b1ff954635acdde14dc92cd9a8 and later · before b91a84299d72ae0e05551e851e47cd3008bd025baffected · git
    • a91befde350375b1ff954635acdde14dc92cd9a8 and later · before dd9e2f5b38f1fdd49b1ab6d3a85f81c14369eaccaffected · git
    • before 6.0not affected · semver
    • 6.1.162 and later · up to and including 6.1.*not affected · semver
    • 6.6.123 and later · up to and including 6.6.*not affected · semver
    • 6.12.69 and later · up to and including 6.12.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.37.1.el10_26.12.0-211.37.1.el10_2

+96

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-2026-23165Feb 14, 2026 · sfc: fix deadlock in RSS config read
    22Monitor
  • ← EarlierCVE-2026-23167Feb 14, 2026 · nfc: nci: Fix race between rfkill and nci_unregister_device().
    18Monitor
  • Later →CVE-2026-23169Feb 14, 2026 · mptcp: fix race in mptcp_pm_nl_flush_addrs_doit()
    18Monitor

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 Linux0acc9ba7a1b5ba4d998c5753e709be904e179b75Vendor (CNA)
Linux Linux78ede9ebd679dadf480dce6f7b798e3603f88348Vendor (CNA)
Linux Linux884b2590ffcc7222cbbd6298051f4c243cc36f5dVendor (CNA)
Linux Linuxb91a84299d72ae0e05551e851e47cd3008bd025bVendor (CNA)
Linux Linuxdd9e2f5b38f1fdd49b1ab6d3a85f81c14369eaccVendor (CNA)
almalinux:kernel6.12.0-211.37.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k6.12.0-211.37.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-core6.12.0-211.37.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug6.12.0-211.37.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-core6.12.0-211.37.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel6.12.0-211.37.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched6.12.0-211.37.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules6.12.0-211.37.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-core6.12.0-211.37.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra6.12.0-211.37.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel6.12.0-211.37.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel-matched6.12.0-211.37.1.el10_2 · AlmaLinux:10Package registry (OSV)
debian:linux6.1.162-1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-211.37.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-211.37.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-211.37.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-211.37.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-211.37.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-211.37.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-211.37.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-devel0:6.12.0-211.37.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-devel-matched0:6.12.0-211.37.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo0:6.12.0-211.37.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo-common-aarch640:6.12.0-211.37.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo-common-ppc64le0:6.12.0-211.37.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)

+11

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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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. Fix✗ → ✓

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

References

Show all references (4 more)

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

All records