---
id: "CVE-2026-118175"
kind: "vulnerability"
aliases: ["CVE-2026-118175"]
title: "Thunderbird: crafted email can leak another message from the same folder"
severity: "medium"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["desktop-email", "end-users", "package", "thunderbird"]
not_affected_if: ["patched-version"]
published_at: "2026-10-27T19:17:29+00:00"
first_seen_at: "2026-10-27T19:33:18+00:00"
updated_at: "2026-10-27T19:35:09+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118175", "first_seen_at": "2026-10-27T19:33:18+00:00"}]
---

# Thunderbird: crafted email can leak another message from the same folder

When a user replies to, forwards, or edits a crafted email as new, Thunderbird can embed parts of a different message stored in the same folder into the draft without showing a blocked-content warning. If the user sends that draft, the content of the other message is disclosed to the recipients.

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

## How to check

- Check the installed Thunderbird version under Help > About Thunderbird, or run `thunderbird --version` where available.
- Check whether the installed version is below `159` or `153.6`.

## Fix

- Update Thunderbird to `159` or to `153.6` or later on the 153 line.

## Timeline

- 2026-10-27T19:33:18+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118175

## From the sources

When replying to, forwarding, or editing a crafted email message as new, Thunderbird could embed parts of a different message stored in the same folder into the message being composed, without showing a blocked content warning. If the user sent the message, the content of the other message was disclosed to the recipients. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.

---

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