# CVE-2026-33809: OOM from malicious IFD offset in golang.org/x/image/tiff

> Attackers can cause denial of service by providing a malicious TIFF file that triggers excessive memory allocation in the Go image library.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Mar 2026
- **Updated:** 6 Apr 2026
- **Also known as:** CLEANSTART-2026-GN98127, CLEANSTART-2026-WK70772, DEBIAN-CVE-2026-33809, GHSA-44p7-9xx4-hf2g, GO-2026-4815, MINI-cwrc-x497-qhwj, MINI-jfpm-8m77-8fgx, MINI-qmqv-mvc7-825c, MINI-vcgc-6g36-635c, MINI-wgqj-c84v-g3f7, MINI-x2fm-fr59-m8xc, UBUNTU-CVE-2026-33809, openSUSE-SU-2026:10628-1

## What is CVE-2026-33809?

CVE-2026-33809 is a medium-severity denial of service vulnerability in golang.org/x/image/tiff, published on 25 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A maliciously crafted TIFF file can cause image decoding to attempt to allocate up 4GiB of memory, causing either excessive resource consumption or an out-of-memory error.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2026-33809?

3 open source packages ship an affected version, including golang.org/x/image. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `golang.org/x/image` | Go | All versions | 0.38.0 |
| `golang.org/x/image` | Go | All versions | 0.38.0 |
| `golang.org/x/image` | Go | All versions | 0.38.0 |
| `pocketbase` | openSUSE:Tumbleweed | All versions | 0.37.3-1.1 |

Products: Golang Tiff.

## How do I fix CVE-2026-33809?

Upgrade golang.org/x/image to 0.38.0 or later.

## Is CVE-2026-33809 being exploited?

There is no known exploitation of CVE-2026-33809 in the wild and no public exploit code.

## Other vulnerabilities in golang.org/x/image/tiff

- [CVE-2026-46604](https://insights.sbomify.com/CVE-2026-46604/): Panic decoding image with out-of-bounds strip offset in x/image/tiff in golang.org/x/image (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33809 and fix it if it is affected.

What it is: CVE-2026-33809 is a medium-severity denial of service vulnerability in golang.org/x/image/tiff, published on 25 Mar 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-2026-33809 in the wild and no public exploit code.

Affected packages and fixed versions:
- golang.org/x/image (Go): affected all versions; fixed in 0.38.0
- golang.org/x/image (Go): affected all versions; fixed in 0.38.0
- golang.org/x/image (Go): affected all versions; fixed in 0.38.0

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-2026-33809/ (Markdown: https://insights.sbomify.com/CVE-2026-33809/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33809
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33809
- OSV: https://osv.dev/vulnerability/CVE-2026-33809

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33809/
Summaries are generated and may contain mistakes; the official description above is the record.