# CVE-2026-64522 — Linux

> As of 2026-07-25, CVE-2026-64522 is a vulnerability in Linux, EPSS 0.1% (6.1th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-64522 as of 2026-07-25; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-07-25

## What is CVE-2026-64522?

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix eswitch mode block underflow on IPsec acquire SA mlx5e_xfrm_add_state() handles acquire-flow temporary SAs by allocating software state and skipping hardware offload setup. That path jumps to the common success label before taking the eswitch mode block. After tunnel-mode validation was moved earlier, the common success label unconditionally calls mlx5_eswitch_unblock_mode(). For acquire SAs, this decrements esw->offloads.num_block_mode without a matching increment. Return directly after installing the acquire SA offload handle, so only the paths that successfully called mlx5_eswitch_block_mode() call the matching unblock.

1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 72 days ago.

## Severity and exploitation probability

- **EPSS (FIRST):** 0.1% probability of exploitation in the next 30 days, higher than 6.1% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 0.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-25

## Is CVE-2026-64522 being exploited?

It currently carries a trending score of 31 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Linux](https://intel.threadlinqs.com/vendors/linux): Linux

## How to fix CVE-2026-64522

No vendor patch reference has been recorded for CVE-2026-64522 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-64522

No threat campaign in the Threadlinqs corpus currently references CVE-2026-64522, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-07-26. 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/b5bd4249e430f5963d559708ee96a671716d2400)
- [git.kernel.org (ecafd8284e527666e83261e6e57a7c7341d591cb)](https://git.kernel.org/stable/c/ecafd8284e527666e83261e6e57a7c7341d591cb)
- [git.kernel.org (abe003b33223ff33552f291644bf35d9c2f992fb)](https://git.kernel.org/stable/c/abe003b33223ff33552f291644bf35d9c2f992fb)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-64522
Full detection coverage and IOCs for threats exploiting CVE-2026-64522 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp