Cross-site scripting via object content sniffing
Published Nov 11, 2025 · Updated Apr 13, 2026
Cross-site scripting in Firefox before 145 and Thunderbird before 145 allows remote attackers to execute script through a crafted webpage. The DOM object-loading path ignores X-Content-Type-Options nosniff for resources lacking Content-Type and sniffs embedded content as active HTML. Exploitation requires user interaction with attacker-controlled content; Thunderbird disables scripting while reading email, while Firefox ESR 115 before 115.30 and ESR 140 before 140.5 are affected.
Summary
What happened
Cross-site scripting in Firefox before 145 and Thunderbird before 145 allows remote attackers to execute script through a crafted webpage. The DOM object-loading path ignores X-Content-Type-Options nosniff for resources lacking Content-Type and sniffs embedded content as active HTML. Exploitation requires user interaction with attacker-controlled content; Thunderbird disables scripting while reading email, while Firefox ESR 115 before 115.30 and ESR 140 before 140.5 are affected.
The record
- CVE
- CVE-2025-13013
- Published
- Nov 11, 2025
- Updated
- Apr 13, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-288, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 11, 2025CVE publishedPublication date reported by the CVE source.
- Apr 13, 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?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- Firefox nosniff bypass via object proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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