---
id: "CVE-2026-115505"
kind: "vulnerability"
aliases: ["CVE-2026-115505"]
title: "libsmb2: integer overflow in DCE/RPC decoder enables heap memory corruption"
severity: "high"
cvss: 7.6
epss: 0.0021
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["c", "libsmb2", "package", "self-hosted", "smb"]
not_affected_if: ["no-share-enumeration", "signed-connections", "trusted-servers-only"]
published_at: "2026-10-22T20:17:06+00:00"
first_seen_at: "2026-10-23T21:57:32+00:00"
updated_at: "2026-10-25T03:14:21+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-115505", "first_seen_at": "2026-10-23T21:57:32+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-115505", "first_seen_at": "2026-10-24T07:15:51+00:00"}]
---

# libsmb2: integer overflow in DCE/RPC decoder enables heap memory corruption

libsmb2 before 6.3 has integer overflows in its DCE/RPC NDR decoder that cause out-of-bounds heap reads and writes. A malicious SMB server or man-in-the-middle on unsigned connections can send crafted NetrShareEnum replies that corrupt client heap memory.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the libsmb2 version linked into your application or shipped in your package manager, e.g. `dpkg -l | grep libsmb2` or `pkg-config --modversion libsmb2`
- Search your code for calls to `smb2_share_enum_async()`
- Check whether SMB connections are made without signing enabled

## Fix

- Upgrade libsmb2 to `6.3` or later
- Require SMB signing on connections where possible

## Timeline

- 2026-10-23T21:57:32+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-115505
- 2026-10-24T07:15:51+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-115505

## From the sources

libsmb2 before 6.3 contains integer overflow vulnerabilities in the DCE/RPC NDR decoder in lib/dcerpc.c that allow heap out-of-bounds reads and writes. A malicious SMB server or machine-in-the-middle on unsigned connections can send crafted NetrShareEnum replies with wrapping actual_count or max_count values when clients call smb2_share_enum_async(), corrupting heap memory.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_