CVE-2026-64564

CRITICAL

sctp: don't free the ASCONF's own transport in DEL-IP processing

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2026-64564. PoCs published by HackSpeak, ethanolgolf.

AI-analyzed exploit summary This repository contains a functional local privilege escalation (LPE) exploit for CVE-2026-64564, a use-after-free (UAF) vulnerability in the Linux SCTP subsystem's ASCONF DEL-IP handling. The exploit leverages controlled memory corruption to achieve root privileges on Debian 13 with kernel 6.12.95 by manipulating SCTP transport objects and kernel memory structures.

Description

In the Linux kernel, the following vulnerability has been resolved: sctp: don't free the ASCONF's own transport in DEL-IP processing sctp_process_asconf() caches the transport the ASCONF chunk is processed against in asconf->transport (== chunk->transport, set once in sctp_rcv()). For an ASCONF located through its Address Parameter by __sctp_rcv_asconf_lookup(), that cached transport corresponds to the Address Parameter, which need not be the packet's source address. sctp_process_asconf_param() rejects a DEL-IP for the packet source address (ADDIP D8, SCTP_ERROR_DEL_SRC_IP), but nothing protects asconf->transport. A single ASCONF can therefore carry, in order: [Address Parameter L] [DEL-IP L] [DEL-IP 0.0.0.0] where L differs from the source. The DEL-IP for L passes the D8 check and calls sctp_assoc_rm_peer() on the transport that asconf->transport still points at, freeing it (RCU-deferred). The following wildcard DEL-IP then reuses the now-dangling asconf->transport in sctp_assoc_set_primary() and sctp_assoc_del_nonprimary_peers(): set_primary() dereferences the freed transport (->ipaddr, ->state) and plants the dangling pointer into asoc->peer.primary_path / active_path, and del_nonprimary_peers(), keeping only the pointer that is no longer on the list, removes every real transport, leaving the association with a transport_count of 0 and primary_path/active_path pointing at freed memory. Reject a DEL-IP that targets the transport the ASCONF is being processed against, mirroring the existing source-address guard, so the wildcard branch can never reuse a freed transport.

Exploits (2)

nomisec WORKING POC 1 stars
by HackSpeak · poc
https://github.com/HackSpeak/CVE-2026-64564

This repository contains a functional local privilege escalation (LPE) exploit for CVE-2026-64564, a use-after-free (UAF) vulnerability in the Linux SCTP subsystem's ASCONF DEL-IP handling. The exploit leverages controlled memory corruption to achieve root privileges on Debian 13 with kernel 6.12.95 by manipulating SCTP transport objects and kernel memory structures.

Classification
Working Poc 98%
Attack Type
Lpe
Complexity
Complex
Reliability
Racy
Target: Linux kernel 6.12.95 (Debian 13), SCTP subsystem
Auth required
Prerequisites: Local user access on the target system · SCTP module loaded and configurable (addip_enable, addip_noauth_enable) · Debian 13 with kernel 6.12.95 (or offsets adapted for other kernels) · Ability to create SCTP sockets and manipulate network namespaces
mistral-large-3 · analyzed Aug 07, 2026 Full analysis →
github WORKING POC
by ethanolgolf · cpoc
https://github.com/ethanolgolf/CVE-2026-64564

This exploit demonstrates a use-after-free (UAF) vulnerability in the Linux kernel's SCTP implementation (ASCONF DEL-IP chunk handling) on Debian 13 with kernel 6.12.95, leading to local privilege escalation (LPE). The PoC manipulates SCTP transport structures and leverages packet spraying techniques to achieve arbitrary memory corruption.

Classification
Working Poc 98%
Attack Type
Lpe
Complexity
Complex
Reliability
Racy
Target: Linux kernel 6.12.95 (Debian 13)
Auth required
Prerequisites: Local user access on Debian 13 (kernel 6.12.95) · SCTP module loaded and enabled · Ability to create network namespaces
mistral-large-3 · analyzed Aug 07, 2026 Full analysis →

Scores

CVSS v3 9.8
EPSS 0.0019
EPSS Percentile 8.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

Status published
Products (16)
linux/Kernel 2.6.25 - 6.6.148linux
linux/Kernel 6.13.0 - 6.18.42linux
linux/Kernel 6.19.0 - 7.1.6linux
linux/Kernel 6.7.0 - 6.12.101linux
Linux/Linux < 2.6.25
Linux/Linux 2.6.25
Linux/Linux 42e30bf3463cd37d73839376662cb79b4d5c416c - 74e8f3e7114f0e26d1b2c4c048044db9fcc27603
Linux/Linux 42e30bf3463cd37d73839376662cb79b4d5c416c - 85aca407c560aba81b5ce9d3d6cf94c74077d19b
Linux/Linux 42e30bf3463cd37d73839376662cb79b4d5c416c - 9b2854f86f0b56e9027d68e7a3fc909d1a9b566f
Linux/Linux 42e30bf3463cd37d73839376662cb79b4d5c416c - d136b29bf91dd8e3161281b87de597b7311d9462
... and 6 more
Published Aug 04, 2026
Tracked Since Aug 04, 2026