DEBIAN-CVE-2025-39967

Advisory lineage Upstream: 1 Downstream: 2
Published: 15 Oct 2025, 08:15
Last modified:28 Apr 2026, 20:30

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
3.1 (osv_debian)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

15 Oct 2025, 08:15
Published
Vulnerability first disclosed
28 Apr 2026, 20:30
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v3.1HIGHScore: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected Systems

  • debianlinux

    < 5.10.247-1 | < 6.1.158-1 | < 6.12.57-1 | < 6.16.10-1

  • debianlinux-6.1

    < 6.1.158-1~deb11u1

References (1)