CVE-2025-12642 Details
lighttpd1.4.80 incorrectly merged trailer fields into headers after http request parsing. This behavior can be exploited to conduct HTTP Header Smuggling attacks.

Successful exploitation may allow an attacker to:

* Bypass access control rules
* Inject unsafe input into backend logic that trusts request headers
* Execute HTTP Request Smuggling attacks under some conditions


This issue affects lighttpd1.4.80
View at NVD
Exploit prediction scoring system (EPSS) score for CVE-2025-12642
EPSS (Exploit Prediction Scoring System): EPSS predicts the likelihood that a vulnerability will be exploited in the wild. A higher percentage means a greater chance of an exploit occurring. The EPSS model produces a probability score between 0 and 1 (0 and 100%).
0.06 Probability of exploitation activity being observed over the next 30 days (20th percentile)
CVSS score for CVE-2025-12642
CVSS (Common Vulnerability Scoring System): An open framework owned and managed by FIRST.Org, Inc. that assigns a numerical score from 0 to 10 to software vulnerabilities to indicate their severity.
9.1 Critical
Products affected by CVE-2025-12642
Lighttpd 1.4.80
DVE Score by Bitsight AI
DVE scores complement traditional static scoring systems like CVSS with Bitsight AI powered real-time threat intelligence and underground cyber criminal activity so that security teams can reduce alert fatigue and focus on vulnerabilities most likely to be exploited.
Low
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CVE-2025-12642 Global Footprint

Top 10 Identified Countries

Country Observations Percentage
US 4 50.00%
FI 2 25.00%
PL 2 25.00%

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CVE-2025-12642 Industry Footprint

Top 10 Identified Industries

*Service provider organizations (typically Technology and Telecommunications) are disproportionally represented in the results given their upstream ownership of end-user infrastructure. See our FAQs.

Industry* Observations Percentage
Technology 4 57.14%
Telecommunications 3 42.86%

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