# CVE-2026-42893: Microsoft Outlook for iOS Tampering Vulnerability

> An attacker can perform tampering via command injection in Microsoft Outlook for iOS, requiring a patch to mitigate the risk.

- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N/E:U/RL:O/RC:C`)
- **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:** No
- **Published:** 12 May 2026
- **Updated:** 10 Aug 2026
- **Also known as:** GHSA-h35m-vhjw-vqxj

## What is CVE-2026-42893?

CVE-2026-42893 is a high-severity command injection vulnerability in Microsoft Outlook, published on 12 May 2026. 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

Improper neutralization of special elements used in a command ('command injection') in M365 Copilot allows an unauthorized attacker to perform tampering over a network.

Weakness: CWE-77 (Improper Neutralization of Special Elements used in a Command)

## Which versions are affected by CVE-2026-42893?

It affects 1 product.


Products: Microsoft Outlook.

## How do I fix CVE-2026-42893?

No fix has been published for CVE-2026-42893 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-42893 being exploited?

There is no known exploitation of CVE-2026-42893 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Outlook

- [CVE-2017-11774](https://insights.sbomify.com/CVE-2017-11774/): Microsoft Office Outlook Security Feature Bypass (high 7.8, exploited in the wild)
- [CVE-2001-0538](https://insights.sbomify.com/CVE-2001-0538/): Code injection in n/a (critical 10.0)
- [CVE-2013-3870](https://insights.sbomify.com/CVE-2013-3870/): Use after free in n/a (critical 9.3)
- [CVE-2010-2728](https://insights.sbomify.com/CVE-2010-2728/): Memory corruption in n/a (critical 9.3)
- [CVE-2010-0266](https://insights.sbomify.com/CVE-2010-0266/): Code injection in n/a (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42893 and fix it if it is affected.

What it is: CVE-2026-42893 is a high-severity command injection vulnerability in Microsoft Outlook, published on 12 May 2026. 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-2026-42893 in the wild and no public exploit code.

Affected product: Microsoft Outlook. 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-2026-42893/ (Markdown: https://insights.sbomify.com/CVE-2026-42893/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42893
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42893
- OSV: https://osv.dev/vulnerability/CVE-2026-42893

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42893/
Summaries are generated and may contain mistakes; the official description above is the record.