cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.43.4, negative chunk-size in chunked Transfer-Encoding causes unbounded memory allocation and process crash. The ChunkedDecoder::read_payload function in cpp-httplib (httplib.h) parses the chunk-size field of HTTP chunked transfer encoding using std::strtoul(). Per the C standard (§7.22.1.4), strtoul silently accepts a leading minus sign, performing unsigned wrap-around: strtoul("-2", …, 16) returns ULONG_MAX − 1 (0xFFFFFFFFFFFFFFFE). The library's only guard (line 12833) rejects ULONG_MAX (the result of "-1"), but any other negative value such as "-2" passes validation. The resulting near-maximum value is stored in chunk_remaining and controls how many bytes the server's read loop consumes from the network. This vulnerability is fixed in 0.43.4.
References
| Link | Resource |
|---|---|
| https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8 | Exploit Vendor Advisory |
| https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8 | Exploit Vendor Advisory |
Configurations
History
02 Jun 2026, 03:16
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8 - Exploit, Vendor Advisory |
01 Jun 2026, 18:35
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Yhirose
Yhirose cpp-httplib |
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| CPE | cpe:2.3:a:yhirose:cpp-httplib:*:*:*:*:*:*:*:* | |
| References | () https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8 - Exploit, Vendor Advisory |
29 May 2026, 20:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-29 20:16
Updated : 2026-06-02 03:16
NVD link : CVE-2026-45352
Mitre link : CVE-2026-45352
CVE.ORG link : CVE-2026-45352
JSON object : View
Products Affected
yhirose
- cpp-httplib