---
title: "CVE-2019-25076\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2019-25076?format=md
keywords: index, follow
---

# CVE-2019-25076

Publication date 8 September 2022

Last updated 2 April 2026

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**5.8 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2019-25076?format=md#impact-score)

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## Description

The TSS (Tuple Space Search) algorithm in Open vSwitch 2.x through 2.17.2
and 3.0.0 allows remote attackers to cause a denial of service (delays of
legitimate traffic) via crafted packet data that requires excessive
evaluation time within the packet classification algorithm for the MegaFlow
cache, aka a Tuple Space Explosion (TSE) attack.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2019-25076?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| openvswitch | 26.04 LTS resolute | Vulnerable, fix deferred |
| 25.10 questing | Ignored end of life, was deferred |
| 25.04 plucky | Ignored end of life, was deferred |
| 24.10 oracular | Ignored end of life, was deferred |
| 24.04 LTS noble | Vulnerable, fix deferred |
| 23.10 mantic | Ignored end of life, was deferred |
| 23.04 lunar | Ignored end of life, was deferred |
| 22.10 kinetic | Ignored end of life, was deferred |
| 22.04 LTS jammy | Vulnerable, fix deferred |
| 20.04 LTS focal | Vulnerable, fix deferred |
| 18.04 LTS bionic | Vulnerable, fix deferred |
| 16.04 LTS xenial | Vulnerable, fix deferred |
| 14.04 LTS trusty | Ignored end of standard support |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Notes

---

### [mdeslaur](https://launchpad.net/~mdeslaur)

as of 2026-04-02, doesn't appear to be an upstream fix available
for this issue.

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

5.8 · Medium

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Changed |
  | Confidentiality impact | None |
  | Integrity impact | None |
  | Availability impact | Low |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 5.8 · Medium |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-25076)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2019-25076)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2019-25076)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2019-25076)

### Other references

* <https://arxiv.org/abs/2011.09107>
* <https://www.youtube.com/watch?v=DSC3m-Bww64>
* <https://www.youtube.com/watch?v=5cHpzVK0D28>
* <https://sites.google.com/view/tuple-space-explosion>
* <https://dl.acm.org/citation.cfm?doid=3359989.3365431>
* <https://www.cve.org/CVERecord?id=CVE-2019-25076>