# CVE-2026-64518 — Linux

> As of 2026-07-25, CVE-2026-64518 is a vulnerability in Linux, EPSS 0.1% (6.3th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-64518 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-2026-64518?

In the Linux kernel, the following vulnerability has been resolved: tcp: Fix out-of-bounds access for twsk in tcp_ao_established_key(). lockdep_sock_is_held() was added in tcp_ao_established_key() by the cited commit. It can be called from tcp_v[46]_timewait_ack() with twsk. Since it does not have sk->sk_lock, the lockdep annotation results in out-of-bound access. $ pahole -C tcp_timewait_sock vmlinux | grep size /* size: 288, cachelines: 5, members: 8 */ $ pahole -C sock vmlinux | grep sk_lock socket_lock_t sk_lock; /* 440 192 */ Let's not use lockdep_sock_is_held() for TCP_TIME_WAIT.

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 6.3% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 0.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-25

## Is CVE-2026-64518 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-2026-64518

No vendor patch reference has been recorded for CVE-2026-64518 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-2026-64518

No threat campaign in the Threadlinqs corpus currently references CVE-2026-64518, 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, GitHub Security Advisories. 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/87bb3e719042f0030a6dad39118c6a6b2a491ad9)
- [git.kernel.org (510db031ba6eb40134f84c90ef963ea4b6dfb878)](https://git.kernel.org/stable/c/510db031ba6eb40134f84c90ef963ea4b6dfb878)
- [git.kernel.org (29cf64d128c94cf98d1c69d8b2962d39db5ff4c6)](https://git.kernel.org/stable/c/29cf64d128c94cf98d1c69d8b2962d39db5ff4c6)
- [git.kernel.org (03cb001ef87b3f8d859cf7f96329acf3d6235d29)](https://git.kernel.org/stable/c/03cb001ef87b3f8d859cf7f96329acf3d6235d29)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-64518
Full detection coverage and IOCs for threats exploiting CVE-2026-64518 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp