CVE-2026-45866Public exploit

Kernel compromise via CAIF serial TTY race

Published May 27, 2026 · Updated May 27, 2026

Use-after-free in the Linux kernel CAIF serial driver allows local users to corrupt kernel memory during concurrent device closure and transmission. ldisc_close() drops the ser->tty reference while the network device remains active, so handle_tx() can dereference the freed TTY during packet transmission. The race requires local access to a configured CAIF serial line discipline; successful triggering can crash the kernel or alter kernel execution.

CVSS severity7.8
High
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel CAIF serial driver allows local users to corrupt kernel memory during concurrent device closure and transmission. ldisc_close() drops the ser->tty reference while the network device remains active, so handle_tx() can dereference the freed TTY during packet transmission. The race requires local access to a configured CAIF serial line discipline; successful triggering can crash the kernel or alter kernel execution.

The record

CVE
CVE-2026-45866
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.11
  2. Affected versionversion=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <308e7e4d0a846359685f40aade023aee7b27284c
  3. Affected versionversion=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <331e2b7051635780edea248dd08ae2026c126f4a
  4. Affected versionversion=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <40962f2bf8cdba63af23aec95ad3f49b689e58e2
  5. Affected versionversion=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <4e63d6f68544ae5269ac9735ae5b69b59b5b8725
  6. Affected versionversion=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <52731ef4438155cea782fac74e547a327ab9e7c5
  7. Affected versionversion=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <5e266ba8d330d3b8e5bc198f238cd8901826cfa1
  8. Affected versionversion=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <c8c197aaa56b25a2d54f3aa07e27e228d6c08546
  9. Affected versionversion=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <d3c75db4e0460641dbcd274b40867e252d801da1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.11; version=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <308e7e4d0a846359685f40aade023aee7b27284c; version=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <331e2b7051635780edea248dd08ae2026c126f4a; version=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <40962f2bf8cdba63af23aec95ad3f49b689e58e2; version=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <4e63d6f68544ae5269ac9735ae5b69b59b5b8725; version=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <52731ef4438155cea782fac74e547a327ab9e7c5; version=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <5e266ba8d330d3b8e5bc198f238cd8901826cfa1; version=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <c8c197aaa56b25a2d54f3aa07e27e228d6c08546; version=56e0ef527b184b3de2d7f88c6190812b2b2ac6bf <d3c75db4e0460641dbcd274b40867e252d801da1

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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