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Vulnerability record · CVE-2026-32941 · published 20 March 2026

CVE-2026-32941: Bishopfox sliver allocation without limits vulnerability

Bishopfox · Sliver

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.

5.7 CVSS 4.0 Medium EPSS 0.44% · top 63.9% CWE-770 · Allocation without limitsCWE-789 · CWE-789
5.7CVSS 4.0 base score
0.44%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
1References, 1 tagged exploit
17 Jun 2026Last modified by NVD

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.

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/BishopFox/sliver/security/advisories/GHSA-97vp-pwqj-46qc ExploitVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

8.1CVE-2023-34758Bishopfox sliver broken cryptographic algorithm vulnerabilitySliver from v1.5.x to v1.5.39 has an improper cryptographic implementation, which allows attackers to execute a man-in-the-middle attack via intercep…EPSS 0.59%7.5CVE-2026-25791Bishopfox sliver missing authentication for critical function vulnerabilitySliver is a command and control framework that uses a custom Wireguard netstack. Prior to 1.7.0, the DNS C2 listener accepts unauthenticated TOTP boo…EPSS 0.50%6.9CVE-2025-27090Bishopfox sliver server-side request forgery (ssrf) vulnerabilitySliver is an open source cross-platform adversary emulation/red team framework, it can be used by organizations of all sizes to perform security test…EPSS 0.63%6.5CVE-2026-25760Bishopfox sliver path traversal vulnerabilitySliver is a command and control framework that uses a custom Wireguard netstack. Prior to 1.6.11, a path traversal in the website content subsystem l…EPSS 0.52%5.9CVE-2026-34227Bishopfox sliver missing authentication for critical function vulnerabilitySliver is a command and control framework that uses a custom Wireguard netstack. Prior to version 1.7.4, a single click on a malicious link gives an …EPSS 0.47%2.1CVE-2026-29781Bishopfox sliver null pointer dereference vulnerabilitySliver is a command and control framework that uses a custom Wireguard netstack. In versions from 1.7.3 and prior, a vulnerability exists in the Sliv…EPSS 0.52%8.6CVE-2020-3569Cisco IOS XR DVMRP IGMP packet handling memory exhaustionCisco IOS XR Software mishandles IGMP packets in its Distance Vector Multicast Routing Protocol (DVMRP) feature, allowing crafted traffic to crash th…KEVEPSS 3.3%analysed8.6CVE-2020-3566Cisco IOS XR DVMRP IGMP queue flaw causes memory exhaustionCisco IOS XR Software mishandles queue management for IGMP packets in its DVMRP feature, allowing uncontrolled memory consumption. An unauthenticated…KEVEPSS 3.7%analysed

Source: NIST National Vulnerability Database (record CVE-2026-32941), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.