# CVE-2022-49086: net: openvswitch: fix leak of nested actions

> A memory leak in the Linux kernel's Open vSwitch module allows attackers to cause denial of service via high-rate flow rotation.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Feb 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-49086, GHSA-jpcv-cqh9-hpf3, UBUNTU-CVE-2022-49086

## What is CVE-2022-49086?

CVE-2022-49086 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

net: openvswitch: fix leak of nested actions

While parsing user-provided actions, openvswitch module may dynamically
allocate memory and store pointers in the internal copy of the actions.
So this memory has to be freed while destroying the actions.

Currently there are only two such actions: ct() and set().  However,
there are many actions that can hold nested lists of actions and
ovs_nla_free_flow_actions() just jumps over them leaking the memory.

For example, removal of the flow with the following actions will lead
to a leak of the memory allocated by nf_ct_tmpl_alloc():

  actions:clone(ct(commit),0)

Non-freed set() action may also leak the 'dst' structure for the
tunnel info including device references.

Under certain conditions with a high rate of flow rotation that may
cause significant memory leak problem (2MB per second in reporter's
case).  The problem is also hard to mitigate, because the user doesn't
have direct control over the datapath flows generated by OVS.

Fix that by iterating over all the nested actions and freeing
everything that needs to be freed recursively.

New build time assertion should protect us from this problem if new
actions will be added in the future.

Unfortunately, openvswitch module doesn't use NLA_F_NESTED, so all
attributes has to be explicitly checked.  sample() and clone() actions
are mixing extra attributes into the user-provided action list.  That
prevents some code generalization too.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2022-49086?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49086?

Apply the vendor's patch.

## Is CVE-2022-49086 being exploited?

There is no known exploitation of CVE-2022-49086 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-49086 and fix it if it is affected.

What it is: CVE-2022-49086 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-49086 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2022-49086/ (Markdown: https://insights.sbomify.com/CVE-2022-49086/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49086
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49086
- OSV: https://osv.dev/vulnerability/CVE-2022-49086

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49086/
Summaries are generated and may contain mistakes; the official description above is the record.