# CVE-2026-80580: fbdev: bound mode sysfs output to the sysfs buffer

CVE-2026-80580 is fixed in 13 products on 1 platform, first by DEBIAN-CVE-2026-80580, released September 4, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-80580
- Priority: High
- CVSS: 7.8 (Low)
- EPSS: 0.0011
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 26, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-80580

## Description

In the Linux kernel, the following vulnerability has been resolved:  fbdev: bound mode sysfs output to the sysfs buffer  mode_string() uses snprintf() which can return a value larger than the remaining buffer space. show_modes() accumulates the return value into i without checking whether i has reached PAGE_SIZE, causing the offset to advance past the sysfs buffer if the modelist is long enough.  Add a size parameter to mode_string() and use scnprintf() to return only the bytes actually written. Add an early return when offset already exceeds the buffer. In show_modes(), stop accumulating once the buffer is full.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-default sles 15.6 | 6.4.0-150600.23.138.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-default sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-default-base sles 15.6 | 6.4.0-150600.23.138.1.150600.12.64.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.84.1.150700.17.47.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-docs sles 15.6 | 6.4.0-150600.23.138.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-livepatch-SLE15-SP6_Update_32 sles 15.6 | 1-150600.13.3.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-livepatch-SLE15-SP7-RT_Update_21 sles 15.7 | 1-150700.1.3.1 | [SUSE-SU-2026:4640-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4640-1.md) | Nov 7, 2026 |
| Linux | kernel-livepatch-SLE15-SP7_Update_22 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-obs-build sles 15.6 | 6.4.0-150600.23.138.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-source sles 15.6 | 6.4.0-150600.23.138.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-source sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-syms sles 15.6 | 6.4.0-150600.23.138.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | linux Debian 14 | 7.1.10-1 | [DEBIAN-CVE-2026-80580](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80580.md) | Sep 4, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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