# CVE-2026-28435: cpp-httplib: cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library

CVE-2026-28435 is fixed in cpp-httplib on 1 platform by DEBIAN-CVE-2026-28435 (version 0.41.0+ds-3), released March 4, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-28435
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0048
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 4, 2026

## Description

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.35.0, cpp-httplib (httplib.h) does not enforce Server::set_payload_max_length() on the decompressed request body when using HandlerWithContentReader (streaming ContentReader) with Content-Encoding: gzip (or other supported encodings). A small compressed payload can expand beyond the configured payload limit and be processed by the application, enabling a payload size limit bypass and potential denial of service (CPU/memory exhaustion). This vulnerability is fixed in 0.35.0.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | cpp-httplib Debian 14 | 0.41.0+ds-3 | [DEBIAN-CVE-2026-28435](https://patchblox.com/security/data/fix/linux/debian-cve-2026-28435.md) | Mar 4, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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