# CVE-2026-33819: Microsoft Bing Remote Code Execution Vulnerability

> An unauthorized attacker can execute arbitrary code remotely via deserialization of untrusted data in Microsoft Bing.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Apr 2026
- **Updated:** 15 Oct 2026
- **Also known as:** GHSA-97j9-4xhc-69qj

## What is CVE-2026-33819?

CVE-2026-33819 is a critical unsafe deserialization vulnerability in Microsoft Bing, published on 23 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Deserialization of untrusted data in Microsoft Bing allows an unauthorized attacker to execute code over a network.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-33819?

It affects 1 product.


Products: Microsoft Bing.

## How do I fix CVE-2026-33819?

No fix has been published for CVE-2026-33819 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-33819 being exploited?

There is no known exploitation of CVE-2026-33819 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Bing

- [CVE-2026-32186](https://insights.sbomify.com/CVE-2026-32186/): Microsoft Bing Elevation of Privilege Vulnerability (critical 10.0)
- [CVE-2025-21355](https://insights.sbomify.com/CVE-2025-21355/): Microsoft Bing Remote Code Execution Vulnerability (high 8.6)
- [CVE-2014-1670](https://insights.sbomify.com/CVE-2014-1670/): Code injection in n/a (medium 6.8)
- [CVE-2026-26120](https://insights.sbomify.com/CVE-2026-26120/): Microsoft Bing Tampering Vulnerability (medium 6.5)
- [CVE-2020-1329](https://insights.sbomify.com/CVE-2020-1329/): Cross-site scripting in Microsoft Bing Search for Android (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33819 and fix it if it is affected.

What it is: CVE-2026-33819 is a critical unsafe deserialization vulnerability in Microsoft Bing, published on 23 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-33819 in the wild and no public exploit code.

Affected product: Microsoft Bing. 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-2026-33819/ (Markdown: https://insights.sbomify.com/CVE-2026-33819/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33819
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33819
- OSV: https://osv.dev/vulnerability/CVE-2026-33819

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33819/
Summaries are generated and may contain mistakes; the official description above is the record.