GHSA-rp3h-jf77-q9p4 CVE-2026-95838 GO-2026-6796
containerd: Unpack DoS via repeated opaque whiteouts
- Severity
- 0.0 / 10
- Medium · CVSS 4.0
- Exploit chance (EPSS)
- 0.22%
- Chance of exploitation in the next 30 days. Higher than 12.96% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Fix
- Available
- 2 packages have a fixed version
Description
Impact
A vulnerability exists in containerd's layer unpack handler where the processing of certain image layers causes superlinear time complexity. During the unpack operation, specific file configurations within the layer can trigger repeated directory traversals.
Consequently, pulling or importing a maliciously crafted image can result in increased unpack times and a moderate increase in CPU usage. This delays container startup, even if the compressed image layers are small. Additionally, in orchestrators like Kubernetes that apply concurrency limits to image pulls, these excessively long operations can reduce the available concurrency for other pulls, potentially delaying unrelated container deployments.
Patches
This bug has been fixed in containerd 2.3.5, 2.2.8, 2.0.12, and 1.7.35. Users should update to these versions to resolve the issue.
Workarounds
There are no known workarounds for this issue. Users are advised to only pull and import trusted images from known registries until the patch can be applied.
Credits
The containerd project would like to thank Jakub Ciolek of AlphaSense for responsibly disclosing this issue in accordance with the containerd security policy.
For more information
If you have any questions or comments about this advisory:
- Open an issue in containerd
- Email us at security@containerd.io
To report a security issue in containerd:
- Report a new vulnerability
- Email us at security@containerd.io
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| github.com/containerd/containerd | < 1.7.35 |
1.7.35 |
| github.com/containerd/containerd/v2 | < 2.0.12 |
2.0.12 |
| github.com/containerd/containerd/v2 | >= 2.2.0, < 2.2.8 |
2.2.8 |
| github.com/containerd/containerd/v2 | >= 2.3.0, < 2.3.5 |
2.3.5 |
| github.com/containerd/containerd/v2 | < 2.0.12>= 2.2.0, < 2.2.8>= 2.3.0, < 2.3.5 |
2.0.122.2.82.3.5 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
github.com/containerd/containerd Go → 1.7.35
- go
go get github.com/containerd/containerd@v1.7.35 && go mod tidy
github.com/containerd/containerd/v2 Go → 2.0.12
- go
go get github.com/containerd/containerd/v2@v2.0.12 && go mod tidy
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- Attack vector
- Local
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- Active
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- None
- Availability (vulnerable system)
- Low
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
Weakness
CWE-400: Uncontrolled Resource Consumption
The product does not properly control the allocation and maintenance of a limited resource.
How to prevent it
- Architecture and Design: Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
- Architecture and Design: Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed. The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
- Architecture and Design: Ensure that protocols have specific limits of scale placed on them.
- Implementation: Ensure that all failures in resource allocation place the system into a safe posture.
CWE-407: Inefficient Algorithmic Complexity
An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GO-2026-6791 containerd CRI plugin: Checkpoint restore bypasses destination security context | High | Also affects github.com/containerd/containerd |
| GHSA-pg57-6jwg-q645 Containerd has image-pull DoS via crafted OCI index graph amplification | Medium | Also affects github.com/containerd/containerd |
| GHSA-7jxh-36q5-gcqv containerd: CRI ExecSync Goroutine Leak Leads to Node-Level Denial of Service | Medium | Also affects github.com/containerd/containerd |
| GO-2026-5064 containerd CRI checkpoint restore CDI annotation smuggling | Critical | Also affects github.com/containerd/containerd |
| GO-2026-5622 Arbitrary host CRI log file read via symlink following in CRI checkpoint restore | Medium | Also affects github.com/containerd/containerd |
| GHSA-xhf5-7wjv-pqxp containerd CRI — image-config `LABEL` flows to restart-monitor `binary://` logger: host-root command execution from an image pull | High | Also affects github.com/containerd/containerd |
| GO-2026-5338 containerd: CRI checkpoint import allows local image tag poisoning | Critical | Also affects github.com/containerd/containerd |
| GHSA-jpcc-p29g-p8mq containerd image-triggered runtime DoS via unbounded group parsing | Medium | Also affects github.com/containerd/containerd |
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