Mozilla Firefox up to 153.4 File improper authorization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.0$5k-$25k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Mozilla Firefox up to 153.4. The affected element is an unknown function of the component File Handler. Performing a manipulation results in improper authorization. This vulnerability is identified as CVE-2026-109783. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Mozilla Firefox up to 153.4. This affects an unknown functionality of the component File Handler. The manipulation with an unknown input leads to a improper authorization vulnerability. CWE is classifying the issue as CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox ESR 153.5.

The advisory is shared at bugzilla.mozilla.org. This vulnerability is uniquely identified as CVE-2026-109783 since 10/13/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. 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 10/13/2026). MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

Upgrading to version 153.5 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: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
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: Improper authorization
CWE: CWE-285 / CWE-266
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 153.5

Timelineinfo

10/13/2026 Advisory disclosed
10/13/2026 +0 days CVE reserved
10/13/2026 +0 days VulDB entry created
10/13/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-109783 (🔒)
GCVE (CVE): GCVE-0-2026-109783
GCVE (VulDB): GCVE-100-417621

Entryinfo

Created: 10/13/2026 15:43
Changes: 10/13/2026 15:43 (57)
Complete: 🔍
Cache ID: 216::103

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