CVE-2025-39967
fbcon: fix integer overflow in fbcon_do_set_font
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.
INFO
Published Date :
Oct. 15, 2025, 8:15 a.m.
Last Modified :
Feb. 3, 2026, 2:12 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Validate all font size calculations with overflow checking.
- Ensure safe multiplication and addition operations.
- Apply patches to the Linux kernel.
- Update the Linux kernel to a secure version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-39967.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-39967 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-39967
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-39967 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-39967 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Feb. 03, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-190 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:5.9:-:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.9:rc7:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.9:rc8:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.9:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.9:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.9:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.194 *cpe:2.3:o:linux:linux_kernel:5.9:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.17:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.17:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.17:rc7:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.16.10 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.14.196 up to (excluding) 4.15 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.19.143 up to (excluding) 4.20 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.4.235 up to (excluding) 4.5 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.9.235 up to (excluding) 4.10 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.155 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.4.62 up to (excluding) 5.4.300 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.8.6 up to (excluding) 5.9 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.9.1 up to (excluding) 5.10.245 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.109 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.50 Added Reference Type kernel.org: https://git.kernel.org/stable/c/1a194e6c8e1ee745e914b0b7f50fa86c89ed13fe Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/4a4bac869560f943edbe3c2b032062f6673b13d3 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/994bdc2d23c79087fbf7dcd9544454e8ebcef877 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/9c8ec14075c5317edd6b242f1be8167aa1e4e333 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a6eb9f423b3db000aaedf83367b8539f6b72dcfc Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/adac90bb1aaf45ca66f9db8ac100be16750ace78 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/b8a6e85328aeb9881531dbe89bcd2637a06c3c95 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/c0c01f9aa08c8e10e10e8c9ebb5be01a4eff6eb7 Types: Patch -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Oct. 15, 2025
Action Type Old Value New Value Added 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. Added Reference https://git.kernel.org/stable/c/1a194e6c8e1ee745e914b0b7f50fa86c89ed13fe Added Reference https://git.kernel.org/stable/c/4a4bac869560f943edbe3c2b032062f6673b13d3 Added Reference https://git.kernel.org/stable/c/994bdc2d23c79087fbf7dcd9544454e8ebcef877 Added Reference https://git.kernel.org/stable/c/9c8ec14075c5317edd6b242f1be8167aa1e4e333 Added Reference https://git.kernel.org/stable/c/a6eb9f423b3db000aaedf83367b8539f6b72dcfc Added Reference https://git.kernel.org/stable/c/adac90bb1aaf45ca66f9db8ac100be16750ace78 Added Reference https://git.kernel.org/stable/c/b8a6e85328aeb9881531dbe89bcd2637a06c3c95 Added Reference https://git.kernel.org/stable/c/c0c01f9aa08c8e10e10e8c9ebb5be01a4eff6eb7