CVE-2022-49871

Kernel memory exhaustion via unreleased NAPI fragments

Published May 1, 2025 · Updated May 11, 2026

Memory leak in the Linux kernel TUN driver allows local users to consume kernel memory through repeated packet writes and interface teardown. The tun_get_user path calls napi_gro_frags without completing NAPI work, leaving GRO_NORMAL fragments queued on napi->rx_list when tun_napi_del removes the interface. Reachability requires a usable TUN file descriptor and interface ownership or CAP_NET_ADMIN; sustained triggering consumes memory rather than exposing kernel contents.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in the Linux kernel TUN driver allows local users to consume kernel memory through repeated packet writes and interface teardown. The tun_get_user path calls napi_gro_frags without completing NAPI work, leaving GRO_NORMAL fragments queued on napi->rx_list when tun_napi_del removes the interface. Reachability requires a usable TUN file descriptor and interface ownership or CAP_NET_ADMIN; sustained triggering consumes memory rather than exposing kernel contents.

The record

CVE
CVE-2022-49871
Published
May 1, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 2025CVE 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=4.15
  2. Affected versionversion=90e33d45940793def6f773b2d528e9f3c84ffdc7 <1118b2049d77ca0b505775fc1a8d1909cf19a7ec
  3. Affected versionversion=90e33d45940793def6f773b2d528e9f3c84ffdc7 <223ef6a94e52331a6a7ef31e59921e0e82d2d40a
  4. Affected versionversion=90e33d45940793def6f773b2d528e9f3c84ffdc7 <3401f964028ac941425b9b2c8ff8a022539ef44a
  5. Affected versionversion=90e33d45940793def6f773b2d528e9f3c84ffdc7 <8b12a020b20a78f62bedc50f26db3bf4fadf8cb9
  6. Affected versionversion=90e33d45940793def6f773b2d528e9f3c84ffdc7 <a4f73f6adc53fd7a3f9771cbc89a03ef39b0b755
  7. Affected versionversion=90e33d45940793def6f773b2d528e9f3c84ffdc7 <d7569302a7a52a9305d2fb054df908ff985553bb

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.15; version=90e33d45940793def6f773b2d528e9f3c84ffdc7 <1118b2049d77ca0b505775fc1a8d1909cf19a7ec; version=90e33d45940793def6f773b2d528e9f3c84ffdc7 <223ef6a94e52331a6a7ef31e59921e0e82d2d40a; version=90e33d45940793def6f773b2d528e9f3c84ffdc7 <3401f964028ac941425b9b2c8ff8a022539ef44a; version=90e33d45940793def6f773b2d528e9f3c84ffdc7 <8b12a020b20a78f62bedc50f26db3bf4fadf8cb9; version=90e33d45940793def6f773b2d528e9f3c84ffdc7 <a4f73f6adc53fd7a3f9771cbc89a03ef39b0b755; version=90e33d45940793def6f773b2d528e9f3c84ffdc7 <d7569302a7a52a9305d2fb054df908ff985553bb

Published CVSS scores

No CVSS assessment is available in this record.

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
T1499Endpoint Denial of Service

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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