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NVD / CVE Program· CNA Linux

CVE-2022-50511: lib/fonts: fix undefined behavior in bit shift for get_default_font

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.16% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 6fe888c4d2fb174408e4540bb2d5602b9f507f90, 890d91b31f4874361e0df047f57d268a7021cb12, 9c14a85e18a58c102ec223144b7edb5b345c1bea.

Low priority for now. Upgrade to Linux Linux 6fe888c4d2fb174408e4540bb2d5602b9f507f90, 890d91b31f4874361e0df047f57d268a7021cb12, 9c14a85e18a58c102ec223144b7edb5b345c1bea or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: lib/fonts: fix undefined behavior in bit shift for get_default_font Shifting signed 32-bit value by 31 bits is undefined, so changing significant bit to unsigned. The UBSAN warning calltrace like below: UBSAN: shift-out-of-bounds in lib/fonts/fonts.c:139:20 left shift of 1 by 31 places cannot be represented in type 'int' <TASK> dump_stack_lvl+0x7d/0xa5 dump_stack+0x15/0x1b ubsan_epilogue+0xe/0x4e __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c get_default_font+0x1c7/0x1f0 fbcon_startup+0x347/0x3a0 do_take_over_console+0xce/0x270 do_fbcon_takeover+0xa1/0x170 do_fb_registered+0x2a8/0x340 fbcon_fb_registered+0x47/0xe0 register_framebuffer+0x294/0x4a0 __drm_fb_helper_initial_config_and_unlock+0x43c/0x880 [drm_kms_helper] drm_fb_helper_initial_config+0x52/0x80 [drm_kms_helper] drm_fbdev_client_hotplug+0x156/0x1b0 [drm_kms_helper] drm_fbdev_generic_setup+0xfc/0x290 [drm_kms_helper] bochs_pci_probe+0x6ca/0x772 [bochs] local_pci_probe+0x4d/0xb0 pci_device_probe+0x119/0x320 really_probe+0x181/0x550 __driver_probe_device+0xc6/0x220 driver_probe_device+0x32/0x100 __driver_attach+0x195/0x200 bus_for_each_dev+0xbb/0x120 driver_attach+0x27/0x30 bus_add_driver+0x22e/0x2f0 driver_register+0xa9/0x190 __pci_register_driver+0x90/0xa0 bochs_pci_driver_init+0x52/0x1000 [bochs] do_one_initcall+0x76/0x430 do_init_module+0x61/0x28a load_module+0x1f82/0x2e50 __do_sys_finit_module+0xf8/0x190 __x64_sys_finit_module+0x23/0x30 do_syscall_64+0x58/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK>

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Oct 7, 2025
Updated
Nov 5, 2026
EPSS
0.1% · 5th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Follow CVE-2022-50511

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  • when exploit code appears or is weaponized
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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel2.6.23.1 and later · before 5.4.229
  • linux linux kernel5.5 and later · before 5.10.163
  • linux linux kernel5.11 and later · before 5.15.86
  • linux linux kernel5.16 and later · before 6.0.16
  • linux linux kernel6.1 and later · before 6.1.2
  • linux linux kernel2.6.23

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2.6.23affected
    • c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 and later · before e039929e36818507e90901edae87f6fa8bc81093affected · git
    • c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 and later · before c9a9aa02f0fa3318e0ae5774f404419a1b4759caaffected · git
    • c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 and later · before e83b47580a0738361772d6f24286adfdaba57e36affected · git
    • c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 and later · before 9c14a85e18a58c102ec223144b7edb5b345c1beaaffected · git
    • c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 and later · before 890d91b31f4874361e0df047f57d268a7021cb12affected · git
    • c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 and later · before 6fe888c4d2fb174408e4540bb2d5602b9f507f90affected · git
    • before 2.6.23not affected · semver
    • 5.4.229 and later · up to and including 5.4.*not affected · semver
    • 5.10.163 and later · up to and including 5.10.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.4-16.1.4-1
Red Hat:enterprise_linux:9::appstreamkernel-64k-debug-debuginfobefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-64k-debug-develbefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-64k-debug-devel-matchedbefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-64k-debuginfobefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-64k-develbefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-64k-devel-matchedbefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-debug-debuginfobefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-debug-develbefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-debug-devel-matchedbefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-debuginfobefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-debuginfo-common-aarch64before 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-debuginfo-common-ppc64lebefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-debuginfo-common-s390xbefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-debuginfo-common-x86_64before 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-develbefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-devel-matchedbefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-docbefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-rt-64k-debug-debuginfobefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-rt-64k-debuginfobefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-rt-debug-debuginfobefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-rt-debuginfobefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-tools-debuginfobefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6
Red Hat:enterprise_linux:9::appstreamkernel-zfcpdump-debuginfobefore 0:5.14.0-570.12.1.el9_60:5.14.0-570.12.1.el9_6

+68

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2023-53673Oct 7, 2025 · Bluetooth: hci_event: call disconnect callback before deleting conn
    31Monitor
  • ← EarlierCVE-2022-50510Oct 7, 2025 · perf/smmuv3: Fix hotplug callback leak in arm_smmu_pmu_init()
    22Monitor
  • Later →CVE-2022-50515Oct 7, 2025 · drm/amdgpu: Fix memory leak in hpd_rx_irq_create_workqueue()
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux6fe888c4d2fb174408e4540bb2d5602b9f507f90Vendor (CNA)
Linux Linux890d91b31f4874361e0df047f57d268a7021cb12Vendor (CNA)
Linux Linux9c14a85e18a58c102ec223144b7edb5b345c1beaVendor (CNA)
Linux Linuxc9a9aa02f0fa3318e0ae5774f404419a1b4759caVendor (CNA)
Linux Linuxe039929e36818507e90901edae87f6fa8bc81093Vendor (CNA)
Linux Linuxe83b47580a0738361772d6f24286adfdaba57e36Vendor (CNA)
debian:linux6.1.4-1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-570.12.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel0:5.14.0-570.12.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel-matched0:5.14.0-570.12.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debuginfo0:5.14.0-570.12.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel0:5.14.0-570.12.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel-matched0:5.14.0-570.12.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-debuginfo0:5.14.0-570.12.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel0:5.14.0-570.12.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel-matched0:5.14.0-570.12.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debuginfo0:5.14.0-570.12.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-aarch640:5.14.0-570.12.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-ppc64le0:5.14.0-570.12.1.el9_6 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records