oesa-2026-2585
Vulnerability from osv_openeuler
A C++11 single-file header-only cross platform HTTP/HTTPS library. It's extremely easy to setup. Just include httplib.h file in your code!
Security Fix(es):
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.(CVE-2026-45352)
cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, when cpp-httplib's server parses an incoming request, it applies percent-decoding to every header value except Location and Referer. The validity check (is_field_value) is run before decoding, so encoded %0D%0A passes the check and is then expanded to a literal \r\n byte pair inside the stored header value. This vulnerability is fixed in 0.44.0.(CVE-2026-45372)
cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, When the server has called Server::set_trusted_proxies() with a non-empty trusted-proxy list, an attacker can send an HTTP request that includes an X-Forwarded-For header whose value parses to no valid IP segments. The code path then executes get_client_ip(), which calls front() on an empty std::vector—undefined behavior in C++. On typical implementations this manifests as abnormal process termination (denial of service). With Sanitizers enabled, you get an explicit runtime diagnostic. This vulnerability is fixed in 0.44.0.(CVE-2026-46527)
| URL | Type | |
|---|---|---|
{
"affected": [
{
"ecosystem_specific": {
"aarch64": [
"cpp-httplib-0.46.0-1.oe2403sp3.aarch64.rpm",
"cpp-httplib-debuginfo-0.46.0-1.oe2403sp3.aarch64.rpm",
"cpp-httplib-debugsource-0.46.0-1.oe2403sp3.aarch64.rpm",
"cpp-httplib-devel-0.46.0-1.oe2403sp3.aarch64.rpm"
],
"src": [
"cpp-httplib-0.46.0-1.oe2403sp3.src.rpm"
],
"x86_64": [
"cpp-httplib-0.46.0-1.oe2403sp3.x86_64.rpm",
"cpp-httplib-debuginfo-0.46.0-1.oe2403sp3.x86_64.rpm",
"cpp-httplib-debugsource-0.46.0-1.oe2403sp3.x86_64.rpm",
"cpp-httplib-devel-0.46.0-1.oe2403sp3.x86_64.rpm"
]
},
"package": {
"ecosystem": "openEuler:24.03-LTS-SP3",
"name": "cpp-httplib",
"purl": "pkg:rpm/openEuler/cpp-httplib\u0026distro=openEuler-24.03-LTS-SP3"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.46.0-1.oe2403sp3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"database_specific": {
"severity": "Critical"
},
"details": "A C++11 single-file header-only cross platform HTTP/HTTPS library. It\u0026amp;apos;s extremely easy to setup. Just include httplib.h file in your code!\r\n\r\nSecurity Fix(es):\n\ncpp-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 (\u00a77.22.1.4), strtoul silently accepts a leading minus sign, performing unsigned wrap-around: strtoul(\u0026quot;-2\u0026quot;, \u2026, 16) returns ULONG_MAX \u2212 1 (0xFFFFFFFFFFFFFFFE). The library\u0026apos;s only guard (line 12833) rejects ULONG_MAX (the result of \u0026quot;-1\u0026quot;), but any other negative value such as \u0026quot;-2\u0026quot; passes validation. The resulting near-maximum value is stored in chunk_remaining and controls how many bytes the server\u0026apos;s read loop consumes from the network. This vulnerability is fixed in 0.43.4.(CVE-2026-45352)\n\ncpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, when cpp-httplib\u0026apos;s server parses an incoming request, it applies percent-decoding to every header value except Location and Referer. The validity check (is_field_value) is run before decoding, so encoded %0D%0A passes the check and is then expanded to a literal \\r\\n byte pair inside the stored header value. This vulnerability is fixed in 0.44.0.(CVE-2026-45372)\n\ncpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, When the server has called Server::set_trusted_proxies() with a non-empty trusted-proxy list, an attacker can send an HTTP request that includes an X-Forwarded-For header whose value parses to no valid IP segments. The code path then executes get_client_ip(), which calls front() on an empty std::vector\u2014undefined behavior in C++. On typical implementations this manifests as abnormal process termination (denial of service). With Sanitizers enabled, you get an explicit runtime diagnostic. This vulnerability is fixed in 0.44.0.(CVE-2026-46527)",
"id": "OESA-2026-2585",
"modified": "2026-08-06T11:11:31Z",
"published": "2026-06-05T11:11:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-2585"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45352"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45372"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46527"
}
],
"schema_version": "1.7.2",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L",
"type": "CVSS_V3"
}
],
"summary": "cpp-httplib security update",
"upstream": [
"CVE-2026-45352",
"CVE-2026-45372",
"CVE-2026-46527"
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
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- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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