CVE-2025-39967

CVE Details

Release Date:	2025-10-15
Impact:	Low	What is this?

Description

In the Linux kernel, the following vulnerability has been resolved: fbcon: fix integer overflow in fbcon_do_set_font Fix integer overflow vulnerabilities in fbcon_do_set_font() where font size calculations could overflow when handling user-controlled font parameters. The vulnerabilities occur when: 1. CALC_FONTSZ(h, pitch, charcount) performs h * pith * charcount multiplication with user-controlled values that can overflow. 2. FONT_EXTRA_WORDS * sizeof(int) + size addition can also overflow 3. This results in smaller allocations than expected, leading to buffer overflows during font data copying. Add explicit overflow checking using check_mul_overflow() and check_add_overflow() kernel helpers to safety validate all size calculations before allocation.

See more information about CVE-2025-39967 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	6.0
Vector String:	CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:H
Version:	3.1
Attack Vector:	Local
Attack Complexity:	Low
Privileges Required:	High
User Interaction:	None
Scope:	Unchanged
Confidentiality Impact:	High
Integrity Impact:	None
Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 7 (kernel-uek)	ELSA-2025-28049	2025-12-12
Oracle Linux version 8 (kernel-uek)	ELSA-2025-28048	2025-12-12
Oracle Linux version 8 (kernel-uek)	ELSA-2025-28049	2025-12-12
Oracle Linux version 9 (kernel-uek)	ELSA-2025-28048	2025-12-12