Improper Output Neutralization for Logs Affecting yhirose/cpp-httplib package, versions [,0.27.0)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-UNMANAGED-YHIROSECPPHTTPLIB-14220404
- published8 Dec 2025
- disclosed5 Dec 2025
- creditnaxus-audit
Introduced: 5 Dec 2025
NewCVE-2025-66577 (opens in a new tab)How to fix?
Upgrade yhirose/cpp-httplib to version 0.27.0 or higher.
Overview
Affected versions of this package are vulnerable to Improper Output Neutralization for Logs via the unconditional acceptance of attacker-supplied HTTP headers in the get_client_ip function. An attacker can manipulate server-visible metadata, logs, and authorization decisions by supplying crafted X-Forwarded-For or X-Real-IP headers, leading to spoofed client IPs being recorded in access and error logs.