CVE-2025-8031Network attack vector

Credential disclosure via unstripped CSP report URLs

Published Jul 22, 2025 · Updated Jul 29, 2026

Information disclosure in Mozilla Firefox and Thunderbird allows remote attackers to obtain HTTP Basic Authentication credentials. The CSP URL sanitizer includes username and password userinfo from a document URL in violation reports instead of removing it before transmission. Exposure requires atypical user behavior and a site using HTTP Basic Authentication with CSP reporting; affected releases include versions before 141 and ESR branches before 128.13 or 140.1.

CVSS severity9.8
Critical
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Mozilla Firefox and Thunderbird allows remote attackers to obtain HTTP Basic Authentication credentials. The CSP URL sanitizer includes username and password userinfo from a document URL in violation reports instead of removing it before transmission. Exposure requires atypical user behavior and a site using HTTP Basic Authentication with CSP reporting; affected releases include versions before 141 and ESR branches before 128.13 or 140.1.

The record

CVE
CVE-2025-8031
Published
Jul 22, 2025
Updated
Jul 29, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-276, T1189
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

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-276Incorrect Default Permissions
T1189Drive-by Compromise

Public exploit references

No public exploit references are available in this record.

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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