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NVD / CVE Program· CNA Linux

CVE-2026-23121: mISDN: annotate data-race around dev->work

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: 0.11% (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 13f3b3b87068898056db4c79ee67052fbde11d43, 7ac345a93af31358e18e9606eb7b354691bf6757, 8175dbf174d487afab81e936a862a8d9b8a1ccb6.

Low priority for now. Upgrade to Linux Linux 13f3b3b87068898056db4c79ee67052fbde11d43, 7ac345a93af31358e18e9606eb7b354691bf6757, 8175dbf174d487afab81e936a862a8d9b8a1ccb6 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: mISDN: annotate data-race around dev->work dev->work can re read locklessly in mISDN_read() and mISDN_poll(). Add READ_ONCE()/WRITE_ONCE() annotations. BUG: KCSAN: data-race in mISDN_ioctl / mISDN_read write to 0xffff88812d848280 of 4 bytes by task 10864 on cpu 1: misdn_add_timer drivers/isdn/mISDN/timerdev.c:175 [inline] mISDN_ioctl+0x2fb/0x550 drivers/isdn/mISDN/timerdev.c:233 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583 x64_sys_call+0x14b0/0x3000 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff88812d848280 of 4 bytes by task 10857 on cpu 0: mISDN_read+0x1f2/0x470 drivers/isdn/mISDN/timerdev.c:112 do_loop_readv_writev fs/read_write.c:847 [inline] vfs_readv+0x3fb/0x690 fs/read_write.c:1020 do_readv+0xe7/0x210 fs/read_write.c:1080 __do_sys_readv fs/read_write.c:1165 [inline] __se_sys_readv fs/read_write.c:1162 [inline] __x64_sys_readv+0x45/0x50 fs/read_write.c:1162 x64_sys_call+0x2831/0x3000 arch/x86/include/generated/asm/syscalls_64.h:20 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000000 -> 0x00000001

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Feb 14, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 1th percentile

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%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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-2026-23121

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 kernel2.6.27 and later · before 5.10.249
  • linux linux kernel5.11 and later · before 5.15.199
  • linux linux kernel5.16 and later · before 6.1.162
  • linux linux kernel6.2 and later · before 6.6.122
  • linux linux kernel6.7 and later · before 6.12.68
  • linux linux kernel6.13 and later · before 6.18.8
  • 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

    • 2.6.27affected
    • 1b2b03f8e514e4f68e293846ba511a948b80243c and later · before d5d99cb9e0839093cd53aa3b28176fce2f820ca0affected · git
    • 1b2b03f8e514e4f68e293846ba511a948b80243c and later · before 13f3b3b87068898056db4c79ee67052fbde11d43affected · git
    • 1b2b03f8e514e4f68e293846ba511a948b80243c and later · before accc3f8266d2a49881dbcf78c459477f4efa0ff3affected · git
    • 1b2b03f8e514e4f68e293846ba511a948b80243c and later · before fc8ba17fd3337bd8b1913c30b95df0fee00d8fb7affected · git
    • 1b2b03f8e514e4f68e293846ba511a948b80243c and later · before aa6e33cd74ca4965f2bbcb025e0b672fb0168a69affected · git
    • 1b2b03f8e514e4f68e293846ba511a948b80243c and later · before 7ac345a93af31358e18e9606eb7b354691bf6757affected · git
    • 1b2b03f8e514e4f68e293846ba511a948b80243c and later · before 8175dbf174d487afab81e936a862a8d9b8a1ccb6affected · git
    • before 2.6.27not affected · semver
    • 5.10.249 and later · up to and including 5.10.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.162-16.1.162-1
Debian:13linuxbefore 6.12.69-16.12.69-1
Debian:14linuxbefore 6.18.8-16.18.8-1

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-2026-23119Feb 14, 2026 · bonding: provide a net pointer to __skb_flow_dissect()
    22Monitor
  • ← EarlierCVE-2026-23120Feb 14, 2026 · l2tp: avoid one data-race in l2tp_tunnel_del_work()
    22Monitor
  • Later →CVE-2026-23122Feb 14, 2026 · igc: Reduce TSN TX packet buffer from 7KB to 5KB per queue
    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 Linux13f3b3b87068898056db4c79ee67052fbde11d43Vendor (CNA)
Linux Linux7ac345a93af31358e18e9606eb7b354691bf6757Vendor (CNA)
Linux Linux8175dbf174d487afab81e936a862a8d9b8a1ccb6Vendor (CNA)
Linux Linuxaa6e33cd74ca4965f2bbcb025e0b672fb0168a69Vendor (CNA)
Linux Linuxaccc3f8266d2a49881dbcf78c459477f4efa0ff3Vendor (CNA)
Linux Linuxd5d99cb9e0839093cd53aa3b28176fce2f820ca0Vendor (CNA)
Linux Linuxfc8ba17fd3337bd8b1913c30b95df0fee00d8fb7Vendor (CNA)
debian:linux6.1.162-1 · 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
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)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

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.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (6 more)

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

All records