---
title: "CVE-2026-71855\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-2026-71855?format=md
keywords: index, follow
---

# CVE-2026-71855

Publication date 21 September 2026

Last updated 21 September 2026

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**5.9 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2026-71855?format=md#impact-score)

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## Description

Suricata is a network Intrusion Detection System, Intrusion Prevention
System and Network Security Monitoring engine. Prior to 7.0.17 and 8.0.6,
src/flow-hash.c can treat an IPv4 and IPv6 flow as equal without comparing
the IP family when their raw address words, ports, protocol, VLAN,
recursion level, live device, and hash bucket align. An IPv6 packet can
therefore reuse IPv4 flow state or the reverse, causing incorrect flowbit
state, detection bypass, or IP-only bypass. This issue is fixed in versions
8.0.6 and 7.0.17.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| suricata | 26.04 LTS resolute | Needs evaluation |
| 24.04 LTS noble | Needs evaluation |
| 22.04 LTS jammy | Needs evaluation |
| 18.04 LTS bionic | Needs evaluation |
| 16.04 LTS xenial | Needs evaluation |

---

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

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

5.9 · Medium

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 5.9 · Medium |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-71855)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-71855)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2026-71855)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2026-71855)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2026-71855>
* <https://github.com/OISF/suricata/security/advisories/GHSA-fvwh-wjcq-2586>
* <https://github.com/OISF/suricata/commit/181b3b2fdd1fe87e4534de4fc79e29a083ef125f>
* <https://github.com/OISF/suricata/commit/4e2f23d031fbcfd72883bacd3d723c9874f23701>
* <https://github.com/OISF/suricata/commit/bc41dcc854e24487d3786ce578a8a86a8350ab20>
* <https://github.com/OISF/suricata/releases/tag/suricata-7.0.17>
* <https://github.com/OISF/suricata/releases/tag/suricata-8.0.6>
* <https://redmine.openinfosecfoundation.org/issues/8558>