CVE-2025-10531Public exploitNetwork attack vectorHinoki check available

CSP bypass via substring-only Vidible shim validation

Published Sep 16, 2025 · Updated Sep 16, 2025

Content Security Policy bypass in Mozilla Firefox and Thunderbird before 143 allows remote attackers to run injected script after a click. The Vidible web-compatibility shim accepts any script URL containing delivery.vidible.tv/jsonp, so a data URL carrying that marker passes its check. Exploitation requires injectable HTML on a page using the shim and interaction with the generated player, enabling script execution despite strict-dynamic CSP.

CVSS severity5.4
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Content Security Policy bypass in Mozilla Firefox and Thunderbird before 143 allows remote attackers to run injected script after a click. The Vidible web-compatibility shim accepts any script URL containing delivery.vidible.tv/jsonp, so a data URL carrying that marker passes its check. Exploitation requires injectable HTML on a page using the shim and interaction with the generated player, enabling script execution despite strict-dynamic CSP.

The record

CVE
CVE-2025-10531
Published
Sep 16, 2025
Updated
Sep 16, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-288, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <143

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <143
Mozilla · Thunderbirdversion=unspecified <143

Published CVSS scores

5.4CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-288Authentication Bypass Using an Alternate Path or Channel
T1189Drive-by Compromise

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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