VDB-427370 · CVE-2026-117999 · EUVD-2026-110898

Mozilla Firefox up to 153.5/158 IPC race condition

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	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	$0-$5k	0.64+

Summaryinfo

A vulnerability was found in Mozilla Firefox up to 153.5/158. It has been declared as critical. This impacts an unknown function of the component IPC. Such manipulation leads to race condition. This vulnerability is referenced as CVE-2026-117999. It is possible to launch the attack remotely. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 153.5/158 and classified as critical. Affected by this issue is some unknown processing of the component IPC. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Race condition in the IPC component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.

The advisory is available at bugzilla.mozilla.org. This vulnerability is handled as CVE-2026-117999 since 10/27/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/27/2026).

Upgrading to version 153.6 or 159 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-110898). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Web Browser

Vendor

Mozilla

Name

Firefox

Version

License

open-source

Website

Vendor: https://www.mozilla.org/
Product: https://www.mozilla.org/en-US/firefox/

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

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 153.6/159

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-2026-117999 (🔒)
GCVE (CVE): GCVE-0-2026-117999
GCVE (VulDB): GCVE-100-427370
EUVD: 🔒

Entryinfo

Created: 10/27/2026 16:05
Updated: 10/27/2026 16:50
Changes: 10/27/2026 16:05 (57), 10/27/2026 16:50 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.