CVE-2021-47162Network attack vector

Kernel compromise via shared TIPC fragment list

Published Mar 25, 2024 · Updated Aug 5, 2026

Use-after-free in Linux TIPC message reassembly allows remote attackers to crash or compromise the kernel via crafted UDP fragments. tipc_buf_append adds a new fragment to a frag_list that can already be cloned and shared without acquiring the additional reference required for every owning socket buffer. A configured, reachable TIPC UDP bearer is required; unauthenticated peers can drive deterministic reuse of the shared fragment and trigger kernel memory corruption or an oops.

CVSS severity9.8
Critical
EPSS probability0.74%
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 TIPC message reassembly allows remote attackers to crash or compromise the kernel via crafted UDP fragments. tipc_buf_append adds a new fragment to a frag_list that can already be cloned and shared without acquiring the additional reference required for every owning socket buffer. A configured, reachable TIPC UDP bearer is required; unauthenticated peers can drive deterministic reuse of the shared fragment and trigger kernel memory corruption or an oops.

The record

CVE
CVE-2021-47162
Published
Mar 25, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 25, 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=4.1.14 <4.2
  2. Affected versionversion=4.2.7 <4.3
  3. Affected versionversion=4.3
  4. Affected versionversion=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <436d650d374329a591c30339a91fa5078052ed1e
  5. Affected versionversion=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <4b1761898861117c97066aea6c58f68a7787f0bf
  6. Affected versionversion=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <5489f30bb78ff0dafb4229a69632afc2ba20765c
  7. Affected versionversion=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <64d17ec9f1ded042c4b188d15734f33486ed9966
  8. Affected versionversion=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <6da24cfc83ba4f97ea44fc7ae9999a006101755c
  9. Affected versionversion=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <ace300eecbccaa698e2b472843c74a5f33f7dce8
  10. Affected versionversion=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <b2c8d28c34b3070407cb1741f9ba3f15d0284b8b
  11. Affected versionversion=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <b7df21cf1b79ab7026f545e7bf837bd5750ac026
  12. Affected versionversion=c19282fd54a19e4651a4e67836cd842082546677
  13. Affected versionversion=d45ed6c1ff20d3640a31f03816ca2d48fb7d6f22

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.1.14 <4.2; version=4.2.7 <4.3; version=4.3; version=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <436d650d374329a591c30339a91fa5078052ed1e; version=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <4b1761898861117c97066aea6c58f68a7787f0bf; version=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <5489f30bb78ff0dafb4229a69632afc2ba20765c; version=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <64d17ec9f1ded042c4b188d15734f33486ed9966; version=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <6da24cfc83ba4f97ea44fc7ae9999a006101755c; version=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <ace300eecbccaa698e2b472843c74a5f33f7dce8; version=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <b2c8d28c34b3070407cb1741f9ba3f15d0284b8b; version=45c8b7b175ceb2d542e0fe15247377bf3bce29ec <b7df21cf1b79ab7026f545e7bf837bd5750ac026; version=c19282fd54a19e4651a4e67836cd842082546677; version=d45ed6c1ff20d3640a31f03816ca2d48fb7d6f22

Published CVSS scores

9.8Linux kernel CVE teamCVSS:3.1/AV:N/AC:L/PR:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-416Use After Free
T1210Exploitation of Remote Services

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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