CVE-2026-29076
cpp-httplib: Stack Overflow Denial of Service (DoS) via std::regex in multipart filename parsing
CVSS Score
5.9
EPSS Score
0.0%
EPSS Percentile
0th
cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.37.0, cpp-httplib uses std::regex (libstdc++) to parse RFC 5987 encoded filename* values in multipart Content-Disposition headers. The regex engine in libstdc++ implements backtracking via deep recursion, consuming one stack frame per input character. An attacker can send a single HTTP POST request with a crafted filename* parameter that causes uncontrolled stack growth, resulting in a stack overflow (SIGSEGV) that crashes the server process. This issue has been patched in version 0.37.0.
| CWE | CWE-674 CWE-1333 |
| Vendor | yhirose |
| Product | cpp-httplib |
| Published | Mar 7, 2026 |
| Last Updated | Mar 9, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
yhirose / cpp-httplib
< 0.37.0