Mozilla Firefox up to 115.40/140.15/153.2/155 XML use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.9$5k-$25k0.00

Summaryinfo

A vulnerability classified as critical has been found in Mozilla Firefox up to 115.40/140.15/153.2/155. The affected element is an unknown function of the component XML. This manipulation causes use after free. The identification of this vulnerability is CVE-2026-92023. It is possible to initiate the attack remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 115.40/140.15/153.2/155. It has been declared as critical. Affected by this vulnerability is some unknown processing of the component XML. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Use-after-free in the XML component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.

It is possible to read the advisory at bugzilla.mozilla.org. This vulnerability is known as CVE-2026-92023 since 09/15/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/28/2026).

The vulnerability scanner Nessus provides a plugin with the ID 350767 (openSUSE 16: MozillaFirefox / MozillaFirefox-branding-upstream / etc (openSUSE-SU-2026:21951-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 115.41, 140.16, 153.3 or 156 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (350767) and CERT Bund (WID-SEC-2026-3375). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Debian Linux
  • IGEL OS
  • SUSE Linux
  • SUSE openSUSE
  • Mozilla Firefox
  • Mozilla Firefox ESR
  • Mozilla Thunderbird

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.9

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

ADP CISA Base Score: 8.8
ADP CISA Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 350767
Nessus Name: openSUSE 16: MozillaFirefox / MozillaFirefox-branding-upstream / etc (openSUSE-SU-2026:21951-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 115.41/140.16/153.3/156

Timelineinfo

09/15/2026 Advisory disclosed
09/15/2026 +0 days CVE reserved
09/15/2026 +0 days VulDB entry created
09/28/2026 +13 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-92023 (🔒)
GCVE (CVE): GCVE-0-2026-92023
GCVE (VulDB): GCVE-100-404179
CERT Bund: WID-SEC-2026-3375 - Mozilla Firefox und Thunderbird: Mehrere Schwachstellen

Entryinfo

Created: 09/15/2026 15:16
Updated: 09/28/2026 02:50
Changes: 09/15/2026 15:16 (57), 09/20/2026 09:22 (12), 09/22/2026 03:09 (7), 09/28/2026 02:50 (2)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion

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