CVE-2022-50511

Service interruption via signed font bitmap shift

Published Oct 7, 2025 · Updated Oct 7, 2025

Undefined bit-shift behavior in the Linux get_default_font function allows local users to interrupt service during framebuffer setup. The function tests a font dimension's top bit with signed 1 shifted by width or height minus one, so a value of 32 shifts into the sign bit and triggers undefined behavior. Reachability requires local execution of the framebuffer-console initialization path; the published impact is limited to availability.

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

What happened

Undefined bit-shift behavior in the Linux get_default_font function allows local users to interrupt service during framebuffer setup. The function tests a font dimension's top bit with signed 1 shifted by width or height minus one, so a value of 32 shifts into the sign bit and triggers undefined behavior. Reachability requires local execution of the framebuffer-console initialization path; the published impact is limited to availability.

The record

CVE
CVE-2022-50511
Published
Oct 7, 2025
Updated
Oct 7, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 7, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 7, 2025Record 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=2.6.23
  2. Affected versionversion=c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 <6fe888c4d2fb174408e4540bb2d5602b9f507f90
  3. Affected versionversion=c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 <890d91b31f4874361e0df047f57d268a7021cb12
  4. Affected versionversion=c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 <9c14a85e18a58c102ec223144b7edb5b345c1bea
  5. Affected versionversion=c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 <c9a9aa02f0fa3318e0ae5774f404419a1b4759ca
  6. Affected versionversion=c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 <e039929e36818507e90901edae87f6fa8bc81093
  7. Affected versionversion=c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 <e83b47580a0738361772d6f24286adfdaba57e36

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.23; version=c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 <6fe888c4d2fb174408e4540bb2d5602b9f507f90; version=c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 <890d91b31f4874361e0df047f57d268a7021cb12; version=c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 <9c14a85e18a58c102ec223144b7edb5b345c1bea; version=c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 <c9a9aa02f0fa3318e0ae5774f404419a1b4759ca; version=c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 <e039929e36818507e90901edae87f6fa8bc81093; version=c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 <e83b47580a0738361772d6f24286adfdaba57e36

Published CVSS scores

5.5UbuntuCVSS: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

T1499Endpoint Denial of Service

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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