---
id: "CVE-2026-116738"
kind: "vulnerability"
aliases: ["CVE-2026-116738"]
title: "VMime: crafted uuencoded email part overflows stack, may run code"
severity: "high"
cvss: 8.8
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["c++", "mail-parsing", "package", "self-hosted", "vmime"]
not_affected_if: ["no-inbound-mime-parsing", "no-vmime-dependency"]
published_at: "2026-10-26T22:16:58+00:00"
first_seen_at: "2026-10-26T22:25:34+00:00"
updated_at: "2026-10-26T22:27:30+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-116738", "first_seen_at": "2026-10-26T22:25:34+00:00"}]
---

# VMime: crafted uuencoded email part overflows stack, may run code

VMime, a C++ mail library, has an integer underflow in its uuencode decoder that causes a stack-based buffer overflow when it parses a crafted uuencoded MIME part. An attacker who sends an email to an application using VMime can crash the application or potentially execute code.

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

## How to check

- unknown

## Fix

- Move to a VMime release newer than `0.9.2` once a fixed version is published; the sources do not name one.

## Timeline

- 2026-10-26T22:25:34+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-116738

## From the sources

VMime through 0.9.2 contains an integer underflow in the uuEncoder::decode function that allows remote attackers to trigger a stack-based buffer overflow via crafted uuencoded MIME parts. Attackers can send an email with a uuencoded line whose length character is 'b' but is not a 'begin' line, corrupting stack memory to crash the application or potentially execute code.

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