Memory Allocation Vulnerability in cpp-httplib by Yhirose
CVE-2026-45352

5.3MEDIUM

Key Information:

Vendor

Yhirose

Status
Cpp-httplib
Vendor
CVE Published:
29 May 2026

What is CVE-2026-45352?

The cpp-httplib library, which is a widely used C++11 header-only HTTP/HTTPS library, contains a vulnerability that allows negative chunk-sizes in chunked Transfer-Encoding, leading to unbounded memory allocation and potential process crashes. This issue arises in the ChunkedDecoder::read_payload function due to improper handling of negative values passed to std::strtoul(). Although the function rejects ULONG_MAX, other negative values like '-2' are accepted, resulting in dangerous behavior during data processing. This vulnerability has been addressed in version 0.43.4.

Affected Version(s)

cpp-httplib < 0.43.4

References

https://github.com/yhirose/cpp-httplib/security/advisorie...
x_refsource_CONFIRM

CVSS V3.1

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

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.