CVE-2022-48809

Service interruption via skb metadata refcount leak

Published Jul 16, 2024 · Updated May 11, 2026

A memory leak in the Linux kernel network stack allows local users to interrupt service by repeatedly uncloning skb destination metadata. tun_dst_unclone increments the new destination-and-metadata object from one reference to two before attaching its sole live reference to the skb, so consuming the skb never frees it. Exploitation requires local low-privileged access and repeated execution of this path, which exhausts kernel memory and interrupts service.

CVSS severity5.5
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A memory leak in the Linux kernel network stack allows local users to interrupt service by repeatedly uncloning skb destination metadata. tun_dst_unclone increments the new destination-and-metadata object from one reference to two before attaching its sole live reference to the skb, so consuming the skb never frees it. Exploitation requires local low-privileged access and repeated execution of this path, which exhausts kernel memory and interrupts service.

The record

CVE
CVE-2022-48809
Published
Jul 16, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 16, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=4.3
  2. Affected versionversion=fc4099f17240767554ff3a73977acb78ef615404 <00e6d6c3bc14dfe32824e2c515f0e0f2d6ecf2f1
  3. Affected versionversion=fc4099f17240767554ff3a73977acb78ef615404 <0be943916d781df2b652793bb2d3ae4f9624c10a
  4. Affected versionversion=fc4099f17240767554ff3a73977acb78ef615404 <4ac84498fbe84a00e7aef185e2bb3e40ce71eca4
  5. Affected versionversion=fc4099f17240767554ff3a73977acb78ef615404 <8b1087b998e273f07be13dcb5f3ca4c309c7f108
  6. Affected versionversion=fc4099f17240767554ff3a73977acb78ef615404 <9eeabdf17fa0ab75381045c867c370f4cc75a613
  7. Affected versionversion=fc4099f17240767554ff3a73977acb78ef615404 <a80817adc2a4c1ba26a7aa5f3ed886e4a18dff88
  8. Affected versionversion=fc4099f17240767554ff3a73977acb78ef615404 <c1ff27d100e2670b03cbfddb9117e5f9fc672540
  9. Affected versionversion=fc4099f17240767554ff3a73977acb78ef615404 <fdcb263fa5cda15b8cb24a641fa2718c47605314

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.3; version=fc4099f17240767554ff3a73977acb78ef615404 <00e6d6c3bc14dfe32824e2c515f0e0f2d6ecf2f1; version=fc4099f17240767554ff3a73977acb78ef615404 <0be943916d781df2b652793bb2d3ae4f9624c10a; version=fc4099f17240767554ff3a73977acb78ef615404 <4ac84498fbe84a00e7aef185e2bb3e40ce71eca4; version=fc4099f17240767554ff3a73977acb78ef615404 <8b1087b998e273f07be13dcb5f3ca4c309c7f108; version=fc4099f17240767554ff3a73977acb78ef615404 <9eeabdf17fa0ab75381045c867c370f4cc75a613; version=fc4099f17240767554ff3a73977acb78ef615404 <a80817adc2a4c1ba26a7aa5f3ed886e4a18dff88; version=fc4099f17240767554ff3a73977acb78ef615404 <c1ff27d100e2670b03cbfddb9117e5f9fc672540; version=fc4099f17240767554ff3a73977acb78ef615404 <fdcb263fa5cda15b8cb24a641fa2718c47605314

Published CVSS scores

6.1Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L
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-401Missing Release of Memory after Effective Lifetime
T1499.004Endpoint Denial of Service: Application 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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