# CVE-2022-1834: Security feature bypass in Thunderbird

> Attackers can spoof sender addresses using Braille spaces to bypass digital signature validation in Thunderbird, misleading users about email authenticity.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 22 Dec 2022
- **Updated:** 16 Apr 2025
- **Also known as:** DEBIAN-CVE-2022-1834, GHSA-qq6h-hx9q-4fxv, UBUNTU-CVE-2022-1834

## What is CVE-2022-1834?

CVE-2022-1834 is a medium-severity vulnerability in Mozilla Thunderbird, published on 22 Dec 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

When displaying the sender of an email, and the sender name contained the Braille Pattern Blank space character multiple times, Thunderbird would have displayed all the spaces. This could have been used by an attacker to send an email message with the attacker's digital signature, that was shown with an arbitrary sender email address chosen by the attacker. If the sender name started with a false email address, followed by many Braille space characters, the attacker's email address was not visible. Because Thunderbird compared the invisible sender address with the signature's email address, if the signing key or certificate was accepted by Thunderbird, the email was shown as having a valid digital signature. This vulnerability affects Thunderbird < 91.10.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2022-1834?

It affects 1 product.


Products: Mozilla Thunderbird.

## How do I fix CVE-2022-1834?

Upgrade to a fixed version.

## Is CVE-2022-1834 being exploited?

There is no known exploitation of CVE-2022-1834 in the wild and no public exploit code.

## Other vulnerabilities in Mozilla Thunderbird

- [CVE-2026-92238](https://insights.sbomify.com/CVE-2026-92238/): Ambiguous parsing of mail headers (critical 9.8)
- [CVE-2026-84637](https://insights.sbomify.com/CVE-2026-84637/): Calendar invitation attachments could launch local executables (critical 9.8)
- [CVE-2021-43529](https://insights.sbomify.com/CVE-2021-43529/): Memory corruption in Thunderbird (critical 9.8)
- [CVE-2019-11703](https://insights.sbomify.com/CVE-2019-11703/): Memory corruption in Thunderbird (critical 9.8)
- [CVE-2019-11704](https://insights.sbomify.com/CVE-2019-11704/): Memory corruption in Thunderbird (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-1834 and fix it if it is affected.

What it is: CVE-2022-1834 is a medium-severity vulnerability in Mozilla Thunderbird, published on 22 Dec 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2022-1834 in the wild and no public exploit code.

Affected product: Mozilla Thunderbird. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-1834/ (Markdown: https://insights.sbomify.com/CVE-2022-1834/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-1834
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-1834
- OSV: https://osv.dev/vulnerability/CVE-2022-1834

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-1834/
Summaries are generated and may contain mistakes; the official description above is the record.