---
title: "CVE-2026-8091\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-2026-8091?format=md
keywords: index, follow
---

# CVE-2026-8091

Publication date 7 May 2026

Last updated 14 May 2026

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**9.8 · Critical**

[Score breakdown](https://ubuntu.com/security/CVE-2026-8091?format=md#impact-score)

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## Description

Incorrect boundary conditions in the Audio/Video: Playback component. This
vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox ESR
140.10.1, Thunderbird 140.10.1, and Firefox ESR 115.35.2.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2026-8091?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| firefox | 26.04 LTS resolute | Not affected |
| 25.10 questing | Not affected |
| 24.04 LTS noble | Not affected |
| 22.04 LTS jammy | Not affected |
| mozjs102 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 24.04 LTS noble | Ignored |
| 22.04 LTS jammy | Ignored |
| mozjs115 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 24.04 LTS noble | Ignored |
| 22.04 LTS jammy | Not in release |
| mozjs38 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 24.04 LTS noble | Not in release |
| 22.04 LTS jammy | Not in release |
| 18.04 LTS bionic | Needs evaluation |
| mozjs52 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 24.04 LTS noble | Not in release |
| 22.04 LTS jammy | Not in release |
| 20.04 LTS focal | Ignored |
| 18.04 LTS bionic | Ignored |
| mozjs68 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 24.04 LTS noble | Not in release |
| 22.04 LTS jammy | Not in release |
| 20.04 LTS focal | Ignored |
| mozjs78 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 24.04 LTS noble | Not in release |
| 22.04 LTS jammy | Ignored |
| mozjs91 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 24.04 LTS noble | Not in release |
| 22.04 LTS jammy | Ignored |
| thunderbird | 26.04 LTS resolute | Not affected |
| 25.10 questing | Not affected |
| 24.04 LTS noble | Not affected |
| 22.04 LTS jammy | Vulnerable |

---

* [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)

mozjs\* contain a copy of the SpiderMonkey JavaScript engine. It
is not feasible to backport security fixes to the mozjs\*
packages, as such, marking them as ignored.
starting with Ubuntu 22.04, the firefox package is just a script
that installs the Firefox snap
starting with Ubuntu 24.04, the thunderbird package is just a
script that installs the Thunderbird snap

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

9.8 · Critical

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 9.8 · Critical |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-8091)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-8091)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2026-8091)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2026-8091)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2026-8091>
* <https://www.mozilla.org/en-US/security/advisories/mfsa2026-30/#CVE-2026-8091>
* <https://www.mozilla.org/en-US/security/advisories/mfsa2026-36/#CVE-2026-8091>
* <https://www.mozilla.org/en-US/security/advisories/mfsa2026-39/#CVE-2026-8091>