CVE-2025-8032Public exploitNetwork attack vector

CSP bypass via lost XSLT source context

Published Jul 22, 2025 · Updated Jul 29, 2026

CSP bypass in Mozilla Firefox before 141 and Thunderbird before 141 allows remote attackers to load cross-origin XML through crafted XSLT. nsSyncLoadService::LoadDocument creates the XSLT document() channel without the loading XML document, so the request does not inherit its CSP. A user must open attacker-controlled XML; affected ESR branches are before 128.13 and 140.1, and the bypass exposes cross-origin data to the transform.

CVSS severity8.1
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CSP bypass in Mozilla Firefox before 141 and Thunderbird before 141 allows remote attackers to load cross-origin XML through crafted XSLT. nsSyncLoadService::LoadDocument creates the XSLT document() channel without the loading XML document, so the request does not inherit its CSP. A user must open attacker-controlled XML; affected ESR branches are before 128.13 and 140.1, and the bypass exposes cross-origin data to the transform.

The record

CVE
CVE-2025-8032
Published
Jul 22, 2025
Updated
Jul 29, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-693, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 22, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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-693Protection Mechanism Failure
T1203Exploitation for Client Execution

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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