Mozilla Firefox up to 159 Layout Positioned use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.0$5k-$25k0.00+

Summaryinfo

A vulnerability was found in Mozilla Firefox up to 159. It has been rated as critical. Affected is an unknown function of the component Layout Positioned. The manipulation leads to use after free. This vulnerability is referenced as CVE-2026-124878. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Mozilla Firefox up to 159. This issue affects an unknown function of the component Layout Positioned. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Use-after-free in the Layout: Positioned component. This vulnerability was fixed in Firefox 160.

The advisory is shared at bugzilla.mozilla.org. The identification of this vulnerability is CVE-2026-124878 since 11/09/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful 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 11/10/2026).

Upgrading to version 160 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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💳💳💳💳💳💳
💳💳💳💳💳💳
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 160

Timelineinfo

11/09/2026 CVE reserved
11/10/2026 +1 days Advisory disclosed
11/10/2026 +0 days VulDB entry created
11/10/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CNA: mozilla
CVE: CVE-2026-124878 (🔒)

GCVE (CVE): GCVE-0-2026-124878
GCVE (VulDB): GCVE-100-433685

Entryinfo

Created: 11/10/2026 14:59
Changes: 11/10/2026 14:59 (57)
Complete: 🔍
Cache ID: 216::103

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