Mozilla Firefox up to 158 WebRender use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.0$5k-$25k0.64+

Summaryinfo

A vulnerability marked as critical has been reported in Mozilla Firefox up to 158. The affected element is an unknown function of the component WebRender. Performing a manipulation results in use after free. This vulnerability is cataloged as CVE-2026-118023. It is possible to initiate the attack remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 158. It has been classified as critical. This affects an unknown code of the component WebRender. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Sandbox escape due to use-after-free in the Graphics: WebRender component. This vulnerability was fixed in Firefox 159.

The advisory is shared at bugzilla.mozilla.org. This vulnerability is uniquely identified as CVE-2026-118023 since 10/27/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/27/2026).

Upgrading to version 159 eliminates this vulnerability.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

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

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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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
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 159

Timelineinfo

10/27/2026 Advisory disclosed
10/27/2026 +0 days CVE reserved
10/27/2026 +0 days VulDB entry created
10/27/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-118023 (🔒)
GCVE (CVE): GCVE-0-2026-118023
GCVE (VulDB): GCVE-100-427389

Entryinfo

Created: 10/27/2026 16:09
Changes: 10/27/2026 16:09 (57)
Complete: 🔍
Cache ID: 216::103

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