HTTP Response Splitting Vulnerability in cpp-httplib by Yhirose
CVE-2026-77341

5.3MEDIUM

Key Information:

Vendor

Yhirose

Status
Cpp-httplib
Vendor
CVE Published:
27 August 2026

What is CVE-2026-77341?

The cpp-httplib library, a C++ header-only HTTP/HTTPS solution, contains a vulnerability in version 0.49.0, allowing unvalidated data to be written directly to the socket during chunked-response trailer output. This oversight permits attackers to inject CRLF sequences within trailer fields, leading to HTTP response splitting. Such exploitation can enable an attacker to craft fraudulent response headers or inject multiple responses, posing significant security risks. Users must upgrade to version 0.50.0, where this issue is addressed.

Affected Version(s)

cpp-httplib >= 0.49.0, < 0.50.0

References

https://github.com/yhirose/cpp-httplib/security/advisorie...
x_refsource_CONFIRM
https://github.com/yhirose/cpp-httplib/commit/568d434e72f...
x_refsource_MISC

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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