CVE-2021-46929

Local privilege escalation via SCTP endpoint use-after-free

Published Feb 27, 2024 · Updated Aug 5, 2026

Use-after-free in Linux kernel SCTP diagnostics allows local users to escalate privileges by racing an association peel-off. sctp_sock_dump reads asoc->base.sk, but the old socket can be freed before lock_sock while its endpoint remains traversable. An unprivileged user can race a local SOCK_DIAG dump or procfs association read against peel-off and close, causing kernel memory corruption or a panic.

CVSS severity8.8
High
EPSS probability0.26%
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 Linux kernel SCTP diagnostics allows local users to escalate privileges by racing an association peel-off. sctp_sock_dump reads asoc->base.sk, but the old socket can be freed before lock_sock while its endpoint remains traversable. An unprivileged user can race a local SOCK_DIAG dump or procfs association read against peel-off and close, causing kernel memory corruption or a panic.

The record

CVE
CVE-2021-46929
Published
Feb 27, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 27, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=4.14
  2. Affected versionversion=d25adbeb0cdb860fb39e09cdd025e9cfc954c5ab <5ec7d18d1813a5bead0b495045606c93873aecbb
  3. Affected versionversion=d25adbeb0cdb860fb39e09cdd025e9cfc954c5ab <75799e71df1da11394740b43ae5686646179561d
  4. Affected versionversion=d25adbeb0cdb860fb39e09cdd025e9cfc954c5ab <769d14abd35e0e153b5149c3e1e989a9d719e3ff
  5. Affected versionversion=d25adbeb0cdb860fb39e09cdd025e9cfc954c5ab <831de271452b87657fcf8d715ee20519b79caef5
  6. Affected versionversion=d25adbeb0cdb860fb39e09cdd025e9cfc954c5ab <8873140f95d4977bf37e4cf0d5c5e3f6e34cdd3e
  7. Affected versionversion=d25adbeb0cdb860fb39e09cdd025e9cfc954c5ab <af6e6e58f7ebf86b4e7201694b1e4f3a62cbc3ec

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.14; version=d25adbeb0cdb860fb39e09cdd025e9cfc954c5ab <5ec7d18d1813a5bead0b495045606c93873aecbb; version=d25adbeb0cdb860fb39e09cdd025e9cfc954c5ab <75799e71df1da11394740b43ae5686646179561d; version=d25adbeb0cdb860fb39e09cdd025e9cfc954c5ab <769d14abd35e0e153b5149c3e1e989a9d719e3ff; version=d25adbeb0cdb860fb39e09cdd025e9cfc954c5ab <831de271452b87657fcf8d715ee20519b79caef5; version=d25adbeb0cdb860fb39e09cdd025e9cfc954c5ab <8873140f95d4977bf37e4cf0d5c5e3f6e34cdd3e; version=d25adbeb0cdb860fb39e09cdd025e9cfc954c5ab <af6e6e58f7ebf86b4e7201694b1e4f3a62cbc3ec

Published CVSS scores

8.8Linux kernel CVE teamCVSS: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 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-416Use After Free
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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