Mozilla Firefox prior 153.1/154 Service Workers cross-domain policy

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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3.0$5k-$25k0.00

Summaryinfo

A vulnerability has been found in Mozilla Firefox and classified as problematic. Affected by this vulnerability is an unknown functionality of the component Service Workers. Performing a manipulation results in cross-domain policy. This vulnerability is identified as CVE-2026-74956. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Mozilla Firefox. This affects an unknown part of the component Service Workers. The manipulation with an unknown input leads to a cross-domain policy vulnerability. CWE is classifying the issue as CWE-942. The product uses a cross-domain policy file that includes domains that should not be trusted. This is going to have an impact on confidentiality. The summary by CVE is:

Same-origin policy bypass in the DOM: Service Workers component. This vulnerability was fixed in Firefox 154 and Firefox ESR 153.1.

It is possible to read the advisory at bugzilla.mozilla.org. This vulnerability is uniquely identified as CVE-2026-74956 since 08/17/2026. The exploitability is told to be difficult. 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. 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 08/18/2026).

Upgrading to version 153.1 or 154 eliminates this vulnerability.

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

Productinfo

Type

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.1
VulDB Meta Temp Score: 3.0

VulDB Base Score: 3.1
VulDB Temp Score: 3.0
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: Cross-domain policy
CWE: CWE-942 / CWE-346 / CWE-345
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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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Firefox 153.1/154

Timelineinfo

08/17/2026 CVE reserved
08/18/2026 +1 days Advisory disclosed
08/18/2026 +0 days VulDB entry created
08/18/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2026-74956 (🔒)
GCVE (CVE): GCVE-0-2026-74956
GCVE (VulDB): GCVE-100-391611

Entryinfo

Created: 08/18/2026 15:15
Changes: 08/18/2026 15:15 (56)
Complete: 🔍
Cache ID: 216::103

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

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