CVE-2026-22977

Kernel crash via unwhitelisted socket control data

Published Jan 21, 2026 · Updated Jan 21, 2026

Denial of service in Linux Kernel 4.16 and later allows local users to crash the kernel by reading a cloned TCP socket error queue. sock_recv_errqueue passes sock_exterr_skb data from the skbuff_fclone_cache cb field directly to put_cmsg, but that cache lacks a permitted usercopy region, so hardened usercopy raises BUG(). Triggering the panic requires CONFIG_HARDENED_USERCOPY, a cloned TCP skb queued for timestamp reporting, and a local recvmsg call with MSG_ERRQUEUE.

CVSS severity5.5
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux Kernel 4.16 and later allows local users to crash the kernel by reading a cloned TCP socket error queue. sock_recv_errqueue passes sock_exterr_skb data from the skbuff_fclone_cache cb field directly to put_cmsg, but that cache lacks a permitted usercopy region, so hardened usercopy raises BUG(). Triggering the panic requires CONFIG_HARDENED_USERCOPY, a cloned TCP skb queued for timestamp reporting, and a local recvmsg call with MSG_ERRQUEUE.

The record

CVE
CVE-2026-22977
Published
Jan 21, 2026
Updated
Jan 21, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 21, 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=4.16
  2. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <005671c60fcf1dbdb8bddf12a62568fd5e4ec391
  3. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <2a71a1a8d0ed718b1c7a9ac61f07e5755c47ae20
  4. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <582a5e922a9652fcbb7d0165c95d5b20aa37575d
  5. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <88dd6be7ebb3153b662c2cebcb06e032a92857f5
  6. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <8c6901aa29626e35045130bac09b75f791acca85
  7. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <c655d2167bf014d4c61b4faeca59b60ff9b9f6b1
  8. Affected versionversion=6d07d1cd300f4c7e16005f881fea388164999cc8 <e00b169eaac5f7cdbf710c354c8fa76d02009115

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.16; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <005671c60fcf1dbdb8bddf12a62568fd5e4ec391; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <2a71a1a8d0ed718b1c7a9ac61f07e5755c47ae20; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <582a5e922a9652fcbb7d0165c95d5b20aa37575d; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <88dd6be7ebb3153b662c2cebcb06e032a92857f5; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <8c6901aa29626e35045130bac09b75f791acca85; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <c655d2167bf014d4c61b4faeca59b60ff9b9f6b1; version=6d07d1cd300f4c7e16005f881fea388164999cc8 <e00b169eaac5f7cdbf710c354c8fa76d02009115

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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