CVE-2026-33997 Moby: Off-by-one error in plugin privilege validation
Attackers can bypass plugin privilege validation during installation, allowing unauthorized privilege escalation in Moby container environments.
- 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
What is CVE-2026-33997?
CVE-2026-33997 is a medium-severity vulnerability in moby, published on 31 Mar 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
Moby is an open source container framework. Prior to version 29.3.1, a security vulnerability has been detected that allows plugins privilege validation to be bypassed during docker plugin install. Due to an error in the daemon's privilege comparison logic, the daemon may incorrectly accept a privilege set that differs from the one approved by the user. Plugins that request exactly one privilege are also affected, because no comparison is performed at all. This issue has been patched in version 29.3.1.
Which versions are affected by CVE-2026-33997?
9 open source packages ship an affected version, including github.com/moby/moby, github.com/docker/docker and github.com/moby/moby/v2. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/moby/moby Go | All versions | None |
github.com/moby/moby Go | All versions | None |
github.com/moby/moby Go | All versions | None |
github.com/docker/docker Go | All versions | None |
github.com/docker/docker Go | All versions | None |
github.com/docker/docker Go | All versions | None |
3 more packages
github.com/moby/moby/v2 Go | All versions | 2.0.0-beta.8 |
github.com/moby/moby/v2 Go | All versions | 2.0.0-beta.8 |
github.com/moby/moby/v2 Go | All versions | 2.0.0-beta.8 |
Products include Docker Engine.
How do I fix CVE-2026-33997?
Apply the vendor's patch.
Is CVE-2026-33997 being exploited?
There is no known exploitation of CVE-2026-33997 in the wild and no public exploit code.
Other vulnerabilities in moby
- CVE-2026-34040 Moby: AuthZ plugin bypass with oversized request body
- CVE-2026-42306 Moby: Race condition in docker cp allows bind mount redirection to host path
- CVE-2026-41568 Moby: Race condition in docker cp allows creation of arbitrary empty files on the host via symlink swap
- CVE-2018-20699 Denial of service in n/a
Sources
Also known as BELL-CVE-2026-33997, CLEANSTART-2026-BP86434, CLEANSTART-2026-FH32149, CLEANSTART-2026-GW50856, CLEANSTART-2026-KV26372, CLEANSTART-2026-PT56990 and 219 more.