Resource exhaustion in Yhirose Cpp-Httplib
CVE-2026-28435
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.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (48.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 48.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002
Affected products
- Yhirose Cpp-Httplib — versions < 0.35.0
Weakness classification (CWE)
References
- github.com/yhirose/cpp-httplib/security/advisories/GHSA-xvfx-w463-6fpp (Exploit, Mitigation, Vendor Advisory)
- github.com/yhirose/cpp-httplib/commit/c99d7472b5cf4869d3897b9afc9792063a3d15a8 (Patch)
Frequently asked questions
- What is CVE-2026-28435?
- CVE-2026-28435 is a high-severity vulnerability in Yhirose Cpp-Httplib, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-03-04.
- How severe is CVE-2026-28435?
- High severity. CVSS v3 base score is 7.5 out of 10.