CVE-2026-32941

MEDIUM

Sliver Vulnerable to Authenticated OOM via Memory Exhaustion in mTLS/WireGuard Transports

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2026-32941. PoCs published by XZ1r0, skoveit.

AI-analyzed exploit summary This repository contains a functional Go-based PoC for CVE-2026-32941, demonstrating an OOM DoS attack against Sliver C2 servers by abusing uncontrolled memory allocation in the socketReadEnvelope function via crafted length prefixes.

Description

Sliver is a command and control framework that uses a custom Wireguard netstack. Versions 1.7.3 and below contain a Remote OOM (Out-of-Memory) vulnerability in the Sliver C2 server's mTLS and WireGuard C2 transport layer. The socketReadEnvelope and socketWGReadEnvelope functions trust an attacker-controlled 4-byte length prefix to allocate memory, with ServerMaxMessageSize allowing single allocations of up to ~2 GiB. A compromised implant or an attacker with valid credentials can exploit this by sending fabricated length prefixes over concurrent yamux streams (up to 128 per connection), forcing the server to attempt allocating ~256 GiB of memory and triggering an OS OOM kill. This crashes the Sliver server, disrupts all active implant sessions, and may degrade or kill other processes sharing the same host. The same pattern also affects all implant-side readers, which have no upper-bound check at all. The issue was not fixed at the the time of publication.

Exploits (2)

github WORKING POC
by XZ1r0 · pythonpoc
https://github.com/XZ1r0/cve-2026-poc-collection/tree/main/other/CVE-2026-32941

This repository contains a functional Go-based PoC for CVE-2026-32941, demonstrating an OOM DoS attack against Sliver C2 servers by abusing uncontrolled memory allocation in the socketReadEnvelope function via crafted length prefixes.

Classification
Working Poc 100%
Attack Type
Dos
Complexity
Moderate
Reliability
Reliable
Target: Sliver C2 (v1.15.16)
Auth required
Prerequisites: Extracted mTLS certificate and private key from a Sliver implant · Network access to the Sliver C2 server
devstral-2 · analyzed May 21, 2026 Full analysis →
nomisec WORKING POC
by skoveit · poc
https://github.com/skoveit/CVE-2026-32941

This repository contains a functional exploit PoC for CVE-2026-32941, a Denial of Service (DoS) vulnerability in Sliver C2. The exploit abuses uncontrolled memory allocation in the socketReadEnvelope function by sending a malicious uint32 length prefix, leading to an OOM crash of the Sliver server.

Classification
Working Poc 95%
Attack Type
Dos
Complexity
Moderate
Reliability
Reliable
Target: Sliver C2
Auth required
Prerequisites: mTLS certificate and private key from a captured or generated Sliver implant
devstral-2 · analyzed Mar 21, 2026 Full analysis →

References (1)

Core 1
Core References

Scores

CVSS v3 6.5
EPSS 0.0006
EPSS Percentile 19.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-770 CWE-789
Status published
Products (3)
bishopfox/sliver < 1.7.3
bishopfox/sliver 0Go
BishopFox/sliver <= 1.7.3
Published Mar 20, 2026
Tracked Since Mar 20, 2026