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.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
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
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 | 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 |
Linux distribution packages (1)
pocketbase openSUSE:Tumbleweed | All versions | 0.37.3-1.1 |
Products include Golang Tiff.
How do I fix CVE-2026-33809?
Upgrade golang.org/x/image to 0.38.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
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
Sources
Also known as CLEANSTART-2026-GN98127, CLEANSTART-2026-WK70772, DEBIAN-CVE-2026-33809, GHSA-44p7-9xx4-hf2g, GO-2026-4815, MINI-cwrc-x497-qhwj and 7 more.