# CVE-2026-92058: Mozilla Firefox use-after-free in Graphics component

Source: https://junglewise.ai/threats/cve-2026-92058-mozilla-firefox-use-after-free-in-graphics-component  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-15. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-92058 · Severity: high · CVSS 8.8 · Published 2026-09-15

Firefox is a widely-used web browser used by millions to access websites and online services. A use-after-free vulnerability in the Graphics component could allow an attacker to execute arbitrary code when a user visits a malicious website, potentially compromising the user's system and sensitive data. The vulnerability affects Firefox, Firefox ESR, Thunderbird, and Thunderbird ESR versions prior to the patched releases.

Technologies: [Mozilla Firefox](https://junglewise.ai/threats/technologies/firefox), [Mozilla Firefox ESR](https://junglewise.ai/threats/technologies/firefox-esr), [Mozilla Thunderbird](https://junglewise.ai/threats/technologies/thunderbird), [Mozilla Thunderbird ESR](https://junglewise.ai/threats/technologies/thunderbird-esr). Vendors: [Mozilla](https://junglewise.ai/threats/vendors/mozilla).

## Quick answers

**Is CVE-2026-92058 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-92058 being exploited in the wild.

**How severe is CVE-2026-92058?** High severity, with a CVSS score of 8.8, published 15 September 2026.

**Which products and versions are affected?** Mozilla Firefox before 156; Mozilla Firefox ESR before 153.3; Mozilla Thunderbird before 156; Mozilla Thunderbird ESR before 153.3.

**Is there a fix for CVE-2026-92058?** A patch was published on 2026-09-15: Fixes released in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-92058 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-92058?** Check whether you run Mozilla Firefox, Mozilla Firefox ESR, Mozilla Thunderbird or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

CVE-2026-92058 is a use-after-free memory safety vulnerability in the Graphics component of Mozilla Firefox and Thunderbird. The vulnerability allows an attacker to trigger a crash or potentially achieve arbitrary code execution by exploiting improper memory management in the Graphics subsystem. The attack is network-based and requires user interaction (visiting a malicious website or opening a crafted file). Mozilla addressed this vulnerability in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.

## Affected products

- Mozilla Firefox before 156
- Mozilla Firefox ESR before 153.3
- Mozilla Thunderbird before 156
- Mozilla Thunderbird ESR before 153.3

## Timeline

- 2026-09-15: disclosed: CVE-2026-92058 publicly disclosed
- 2026-09-15: patched: Fixes released in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3

## References

- [https://bugzilla.mozilla.org/show_bug.cgi?id=2068438](https://bugzilla.mozilla.org/show_bug.cgi?id=2068438)
- [https://www.mozilla.org/security/advisories/mfsa2026-90/](https://www.mozilla.org/security/advisories/mfsa2026-90/)

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