5.5

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

Analyzed
AliasesUBUNTU-CVE-2022-50511DEBIAN-CVE-2022-50511
Published 07-10-2025Last modified 11-05-2026

Vulnerability summary

CVE-2022-50511 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 5.3% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.16%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 5 · Related 4
RHSA-2025:6966SUSE-SU-2025:4111-1SUSE-SU-2025:4139-1SUSE-SU-2025:4149-1SUSE-SU-2025:4320-1

Timeline

  1. 07-10-2025
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

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>

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.16%

Chance of exploitation in the next 30 days

Percentile

5%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.16% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu120 products
  • linuxAll versions (No fix recorded) | < 5.4.0-144.161 | < 5.15.0-69.76
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.4.0-1097.105 | < 5.15.0-1033.37
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ c81f717cb9e0bd91dc4b98753cb2705ab0fe2801, < e039929e36818507e90901edae87f6fa8bc81093 | ≥ c81f717cb9e0bd91dc4b98753cb2705ab0fe2801, < c9a9aa02f0fa3318e0ae5774f404419a1b4759ca | ≥ c81f717cb9e0bd91dc4b98753cb2705ab0fe2801, < e83b47580a0738361772d6f24286adfdaba57e36 | ≥ c81f717cb9e0bd91dc4b98753cb2705ab0fe2801, < 9c14a85e18a58c102ec223144b7edb5b345c1bea | ≥ c81f717cb9e0bd91dc4b98753cb2705ab0fe2801, < 890d91b31f4874361e0df047f57d268a7021cb12 | ≥ c81f717cb9e0bd91dc4b98753cb2705ab0fe2801, < 6fe888c4d2fb174408e4540bb2d5602b9f507f90 | 2.6.23
  • linux_kernel≥ 2.6.23.1, < 5.4.229 | ≥ 5.5, < 5.10.163 | ≥ 5.11, < 5.15.86 | ≥ 5.16, < 6.0.16 | ≥ 6.1, < 6.1.2 | 2.6.23 | 2.6.23:rc2 | 2.6.23:rc3 | 2.6.23:rc4 | 2.6.23:rc5 | 2.6.23:rc6 | 2.6.23:rc7 | 2.6.23:rc8 | 2.6.23:rc9
Debian1 product
  • linux< 6.1.4-1

3 vendors · 123 products

References

10 links