# Use after free in Mozilla Firefox and others

CVE record · `CVE-2022-26486`

- **Identifiers:** `CVE-2022-26486`
- **State:** Confirmed
- **Severity:** CVSS 9.6 Critical
- **Critical:** Yes: KEV, CVSS 9+
- **CNA:** mozilla
- **Weakness (CWE):** [CWE-416](https://cwe.mitre.org/data/definitions/416.html)
- **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md)
- **Technologies:** [Mozilla Firefox](https://agentprime.io/advisories/technology/mozilla-firefox.md) · [Mozilla Firefox ESR](https://agentprime.io/advisories/technology/mozilla-firefox-esr.md) · [Mozilla Firefox for Android](https://agentprime.io/advisories/technology/mozilla-firefox-for-android.md) · [Mozilla Thunderbird](https://agentprime.io/advisories/technology/mozilla-thunderbird.md) · [Mozilla Focus](https://agentprime.io/advisories/technology/mozilla-focus.md)
- **Published:** 22 Dec 2022
- **Updated:** 21 Oct 2025
- **Reviewed by a person:** No

Published by the CVE Program (CNA: mozilla) at 22 Dec 2022, 00:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Critical

Critical, because:

- In CISA’s KEV catalogue since 7 Mar 2022: it is known to be exploited.
- CVSS score 9.6: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected products, as the CNA wrote them

- Vendor: Mozilla. Product: Firefox.
  - affected: `unspecified to before 97.0.2` (custom)
- Vendor: Mozilla. Product: Firefox ESR.
  - affected: `unspecified to before 91.6.1` (custom)
- Vendor: Mozilla. Product: Firefox for Android.
  - affected: `unspecified to before 97.3.0` (custom)
- Vendor: Mozilla. Product: Thunderbird.
  - affected: `unspecified to before 91.6.2` (custom)
- Vendor: Mozilla. Product: Focus.
  - affected: `unspecified to before 97.3.0` (custom)

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 9.6 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H`, from ADP (CISA-ADP)

- **CISA KEV:** Listed since 7 Mar 2022: known to be exploited.
- **EPSS:** 0.024, the 83rd percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 22 Dec 2022. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2022-26486](https://www.cve.org/CVERecord?id=CVE-2022-26486)
- [NVD: CVE-2022-26486](https://nvd.nist.gov/vuln/detail/CVE-2022-26486)

### References from the CNA

- <https://www.mozilla.org/security/advisories/mfsa2022-09/>
- <https://bugzilla.mozilla.org/show_bug.cgi?id=1758070>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2022-26486>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2022-26486/>. Everything for agents: <https://agentprime.io/llms.txt>.