# CVE-2026-31694 — Linux

> As of 2026-07-02, CVE-2026-31694 is a HIGH-severity vulnerability in Linux, CVSS v3.1 7.8, EPSS 0.1% (2.7th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-31694, most recently “Linux Kernel FUSE Page-Cache Buffer Overflow (CVE-2026-31694) Enables Local Privilege Escalation”.

**Last updated:** 2026-07-02

## What is CVE-2026-31694?

In the Linux kernel, the following vulnerability has been resolved: fuse: reject oversized dirents in page cache fuse_add_dirent_to_cache() computes a serialized dirent size from the server-controlled namelen field and copies the dirent into a single page-cache page. The existing logic only checks whether the dirent fits in the remaining space of the current page and advances to a fresh page if not. It never checks whether the dirent itself exceeds PAGE_SIZE. As a result, a malicious FUSE server can return a dirent with namelen=4095, producing a serialized record size of 4120 bytes. On 4 KiB page systems this causes memcpy() to overflow the cache page by 24 bytes into the following kernel page. Reject dirents that cannot fit in a single page before copying them into the readdir cache.

Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 135 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.8 — HIGH (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **EPSS (FIRST):** 0.1% probability of exploitation in the next 30 days, higher than 2.7% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 6/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-05-01, last modified 2026-07-02

## Is CVE-2026-31694 being exploited?

Weaponised exploit code for CVE-2026-31694 is publicly available. 1 public proof-of-concept repository is tracked for this identifier.

- [0xCyberstan/CVE-2026-31694-POC](https://github.com/0xCyberstan/CVE-2026-31694-POC) (github)

## Affected products and versions

- **Linux**: Linux

## How to fix CVE-2026-31694

The record marks a vendor fix as available for CVE-2026-31694. Patch reference: [https://git.kernel.org/stable/c/474ce83c96a55f2eeb14dee2be375eeadfdacdf5](https://git.kernel.org/stable/c/474ce83c96a55f2eeb14dee2be375eeadfdacdf5). Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

## Threat activity tracking CVE-2026-31694

1 tracked threat in the Threadlinqs corpus references CVE-2026-31694, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Linux Kernel FUSE Page-Cache Buffer Overflow (CVE-2026-31694) Enables Local Privilege Escalation](https://intel.threadlinqs.com/threat/TL-2026-1177) — HIGH · 2026-07-10

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-07-10. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [git.kernel.org](https://git.kernel.org/stable/c/7de93abfaae1b2dc94da8a07a36421bd073f1d8f)
- [git.kernel.org (474ce83c96a55f2eeb14dee2be375eeadfdacdf5)](https://git.kernel.org/stable/c/474ce83c96a55f2eeb14dee2be375eeadfdacdf5)
- [git.kernel.org (51a8de6c50bf947c8f534cd73da4c8f0a13e7bed)](https://git.kernel.org/stable/c/51a8de6c50bf947c8f534cd73da4c8f0a13e7bed)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-31694
Full detection coverage and IOCs for threats exploiting CVE-2026-31694 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp